Chemistry

Question 1

Water at room temperature usually has a slightly acidic pH. This is largely attributed to what compound(s)?

a. Sulfuric acid
b. Dissolved metals
c. Carbonic acid
d. Nitric acid

Answer 1

c. Carbonic acid

Question 2

When benzoic acid dissolves in water, it partially reacts with water and ionizes to form benzoate and hydronium ions. In this reaction, what is the conjugate acid?
a. Benzoate ions
b. Hydronium ions
c. Water
d. Benzoic acid

Answer 2

b. Hydronium ions

Question 3

Define a salt in terms of acid and base.
a. A salt is a compound that follows Le Chatelier’s Principle in reactions with other compounds.
b. All of these
c. A salt is a compound formed when the nucleus of a hydrogen tom enters a quantity of water.
d. A salt is a compound (other than water) produced by the reaction of an acid and a base.

Answer 3

d. A salt is a compound (other than water) produced by the reaction of an acid and a base.

Question 4

When a can of soda is opened and CO2 is released to the atmosphere, what is the resultant pH of the soda?
a. Decreases
b. Increases
c. The same
d. All these

Answer 4

b. Increases

Question 5

Which of the following pairs will form a buffer
solution in the course of a titration?

a. Nitric acid, sodium hydroxide
b. Sulfuric acid, potassium hydroxide
c. Acetic acid, sodium hydroxide
d. Hydrochloric acid, potassium hydroxide

Answer 5

c. Acetic acid, sodium hydroxide

Question 6

Buffer capacity is maximum when:

a. pH = 0.5pKa
b. pH = pKa
c. pH = 2pKa
d. pH = 0.1pKa

Answer 6

b. pH = pKa

Question 7

Which of the following acids would be most
suitable for preparing a buffer of pH 3.1?

a. Hydrogen peroxide, pKa = 11.65
b. Propanoic acid, pKa = 4.874
c. Cyanoacetic acid, pKa = 2.472
d. Sulfanilic acid, pKa = 3.232

Answer 7

d. Sulfanilic acid, pKa = 3.232

Question 8

The distance of the Earth to the most remote known
normal galaxy is calculated to be:

a. 2x10^22m
b. 1.4x10^26m
c. 4x10^16m
d. 9x10^25m

Answer 8

d. 9x1025m

Question 9

1. An antique capillary tube is submitted to the National Museum. The said tube, fixed horizontally in its display case, contains a 10 cm air column, being blocked by an 8 cm column of mercury towards the open end of the tube. What will be the length of the air column when the tube is fixed vertically with the open end down, assuming that the pressure prior to changing its orientation is 1 atm?

A. 9.0 cm
B. 10.1 cm
C. 11.2 cm
D.12.3 cm

Answer 9

C. 11.2 cm

Question 10

1. An antique capillary tube is submitted to the National Museum. The said tube, fixed horizontally in its display case, contains a 10 cm air column, being blocked by an 8 cm column of mercury towards the open end of the tube. What will be the length of the air column when the tube is fixed vertically with the open end up, assuming that the pressure prior to changing its orientation is 1 atm?

A. 9.0 cm
B. 10.1 cm
C. 11.2 cm
D.12.3 cm

Answer 10

A. 9.0 cm

Question 11

1. An antique capillary tube is submitted to the National Museum. The said tube, fixed horizontally in its display case, contains a 10 cm air column, being blocked by an 8 cm column of mercury towards the open end of the tube. What will be the length of the air column when the tube is fixed vertically with the open end up but slanted at a 45° from the horizontal, assuming that the pressure prior to changing its orientation is 1 atm?

A. 9.0 cm
B. 9.31 cm
C. 11.2 cm
D.12.3 cm

Answer 11

B. 9.31 cm

Question 12

2. A certain gas confined in a cylinder by a piston, where the initial pressure in the system is 7 bar and the volume is 0.11 cubic meter. The piston is held in place by latches and the apparatus is in vacuum. Determine the change in energy when the latches are removed suddenly and the gas expands to double its initial volume and the piston strikes the latches at the end of the process.

A: 1.54 kJ
B: 0.77 kJ
C: 0.59 kJ
D: No change

Answer 12

D: No change

Question 13

3. A traveler is exploring various locations in the Philippines. During one of her journeys, she realized that she forgot to boil the eggs beforehand. She knows that the average time to boil an egg, under 1 bar, is 3 minutes. If she can boil all of the eggs at the same time, where should she boil the eggs if she can only stop in each location for no more than 3 minutes?

A: Jaro, Iloilo
B: Mandaluyong, Metro Manila
C: Tagum, Davao
D: Cabanatuan, Nueva Ecija

Answer 13

A: Jaro, Iloilo

Question 14

6. What is the empirical formula of the Human DNA?

A: C31H52O34N18P6
B: C37H46O21N10P7
C: C34H55O36N19P2
D: C39H50O22N15P3

Answer 14

D: C39H50O22N15P3

Question 15

Which among the following polymers is the most suitable in creating the most effective bulletproof vest?

A: Polymethacrylate Fiber
B: Polyamide Fiber
C: Polycarbonate Fiber
D: Polyethylene Fiber

Answer 15

D: Polyethylene Fiber

Question 16

Which among the following polymers is the most suitable in creating the most effective bulletproof windows?

A: Polymethacrylate Fiber
B: Polyamide Fiber
C: Polycarbonate Fiber
D: Polyethylene Fiber

Answer 16

C: Polycarbonate Fiber

Question 17

Which among the following polymers is the most suitable in creating plexiglass and acrylites?

A: Polymethacrylate Fiber
B: Polyamide Fiber
C: Polycarbonate Fiber
D: Polyethylene Fiber

Answer 17

A: Polymethacrylate Fiber

Question 18

9. An unmarked container for an organic compound is meant for waste disposal. To properly dispose the compound, samples of it were tested in various ways to gather data that would divulge its identity. The results of the tests are as follows:

[1] – 0.10 g of the compound gave 0.0756 g of water and 0.2882 g of carbon dioxide
[2] – 0.20 g of the compound was able to produce 21.8 mL of nitrogen at 15 deg C and 760 mmHg
[3] – 0.125 g of platinum remained after

0.40 g of the platinichloride of the compound was ignited Assuming the compound is a monoacid organic base, What is its molecular formula?

A: C2H9N3
B: C5H4N3
C: CH3N2
D: C7H9N

Answer 18

D: C7H9N

Question 19

Which subatomic particle gives identity of an element?

A: Proton
B: Electron
C: Neutron
D: A and B

Answer 19

A: Proton

Question 20

To which subatomic particle does each statement refer to:

(a.) Has a positive charge
(b.) Cannot be found inside the nucleus
(c.) Has the smallest mass
(d.) Has a neutral charge

A: Electron, Neutron, Electron, Proton
B: Proton, Electron, Electron, Neutron
C: Neutron, Proton, Neutron, Electron
D: Proton, Electron, Neutron, Proton

Answer 20

B: Proton, Electron, Electron, Neutron

Question 21

Which among the following statements regarding Classical Physics and Quantum Theory is TRUE?

I – Robert Bunsen proposed that Energy, like matter, is discontinuous.
II – Quantum Theory places no limitation on the amount of energy that a system may possess.
III – The energy of a quantum of electromagnetic radiation is proportional to the frequency of the radiation.

A:I,II
B:II,III
C: II only
D. III only

Answer 21

D. III only

Question 22

The precision of knowing a particles momentum indicates that its loci would be impossible to determine is one way of interpreting which among the following?

A: Aufbau Principle
B: Pauli Exclusion Principle
C: Compton Effect
D: Heisenberg Principle

Answer 22

D: Heisenberg Principle

Question 23

Which element constituted the need of a new group in the original design of Dmitri Mendeleev’s Periodic Table?

A: Gallium
B: Argon
C: Mercury
D: Tungsten

Answer 23

B: Argon

Question 24

Which among the following statements is TRUE?

A: Cadmium and Bromine are both diamagnetic.
B: Cadmium and K^+1 can be affected by an external magnetic force.
C: The potassium and chromium ions are both paramagnetic.
D: Cr^3+ is more affected by an external magnetic force in comparison to Bromine.

Answer 24

D: Cr^3+ is more affected by an external magnetic force in comparison to Bromine.

Question 25

What intermolecular forces CH3CHOHCH3 does have? A: Hydrogen Bonding only B: London Forces and Hydrogen Bonding C: Dipole-Dipole Forces and Hydrogen Bonding D: London Forces, Dipole-Dipole Forces, and Hydrogen Bonding

Answer 25

D: London Forces, Dipole-Dipole Forces, and Hydrogen Bonding

Question 26

How many water molecules can attach to methanol via hydrogen bonding? A: 2 B: 3 C: 4 D: 5

Answer 26

B: 3

Question 27

Arrange the following substances in order of increasing magnitude of London Forces: GeCl4, SiCl4, and CCl4. A: GeCl4 < CCl4 < SiCl4 B: CCl4, GeCl4

Answer 27

C: CCl4 < SiCl4 < GeCl4

Question 28

Which among the following substances has the highest surface tension? A:CCl4 B:CH3OH C:CH3CH2OCH2CH3 D:NOTA

Answer 28

B:CH3OH

Question 29

Which among the following is the most soluble acid in ethanol? A: CH3(CH2)14COOH B: CH3COOH C: C17H35COOH D: C18H32O2

Answer 29

B: CH3COOH

Question 30

24. Determine whether the following statements are TRUE or FALSE. (a.) The internal energy of a system comprises that of the energy of every single microscopic particle that makes up that system (b.) Heat and work can be conserved in a system by distributing it evenly amongst the systems constituents (c.) delta U being equal to the summation of heat and work is an interpretation of the First Law of Thermodynamics (d.) delta H can be interpreted as the heat transferred under constant volume conditions. A: False, False, True, True B: True, True, True, True C: False, True, True, False D: True, False, True, False

Answer 30

D: True, False, True, False

Question 31

When methane is combusted with an excess amount of air, carbon dioxide and water vapor is produced. What is the temperature of the product mixture if both reactants were at an initial temperature of 0 deg C? A: 1530 deg C B: 1874 deg C C: 2238 deg C D: 2516 deg C

Answer 31

C: 2238 deg C

Question 32

26. A 58 kg diabetic chemical engineer was given a project that will be conducted at a summit point with an elevation of 1450 m in Mount Katanglad. Conscious of his glucose levels, he decided to determine the amount of it that will be metabolized in the climb. For this purpose, he assumed that the work performed is about four times that required in lifting an equal weight body up the entire elevation. If 70% of the heat from the metabolism of glucose was efficiently converted to work, how much of it was metabolized? A: 146 grams B: 302 grams C: 582 grams D: 795 grams

Answer 32

B: 302 grams

Question 33

Determine whether the following statements are TRUE or FALSE: (a.) Ludwig Boltzmann introduced the concept of entropy and elucidated its behavior in order to explain the direction of spontaneous change (b.) When the temperature of a system is increased, the number of feasible microstates decrease, effectively leading to an increase in entropy (c.) A process wherein two ideal gases in separate bulbs, both at a pressure of 1 bar, are connected and allowed to expand into the total volume, exhibits a positive change in entropy A: True, False, True B: False, False, True C: True, True, False D: False, True, False

Answer 33

B: False, False, True

Question 34

Which among the following relationships fully encapsulates the idea of the Second Law of Thermodynamics A: delta S_system < 0 B: delta S_universe > delta S_system + delta S_surrounding C: delta S_universe > 0 D: delta S_system < delta S_surrounding

Answer 34

C: delta S_universe > 0

Question 35

29. For each of the following processes, determine the trend of the enthalpy and entropy (A.) Ethyl Alcohol evaporating from a glass container (B.) A diatomic molecule dissociates into atoms (C.) Charcoal is burned to form carbon dioxide and water A: delta H > 0, delta S < 0; delta H > 0, delta S < 0; delta H < 0, delta S > 0 B: delta H > 0, delta S > 0; delta H < 0, delta S > 0; delta H > 0, delta S < 0 C: delta H > 0, delta S > 0; delta H > 0, delta S > 0; delta H < 0, delta S > 0 D: delta H < 0, delta S < 0; delta H > 0, delta S < 0; delta H > 0, delta S > 0

Answer 35

C: delta H > 0, delta S > 0; delta H > 0, delta S > 0; delta H < 0, delta S > 0

Question 36

Make an educated guess! Which among the following substances would closely obey Trouton’s Rule? A: Water B: Toluene C: Hydrogen Fluoride D: Butanol

Answer 36

A: Water

Question 37

For the combustion of liquid acetylene in the presence of oxygen, liquid water and carbon dioxide gas is produced. Given this reaction, which among the following statements is TRUE? A: Since delta S is positive, delta G is more negative than delta H B: Since delta S is negative, delta G is more negative than delta H C: Since delta S is positive, delta G is less negative than delta H D: Since delta S is negative, delta G is less negative than delta H

Answer 37

D: Since delta S is negative, delta G is less negative than delta H

Question 38

For the following pairs, determine which system has the greater chemical potential [1] (1A): One mole of liquid water at 100 deg C or (1B): One mole of water vapor at 100 deg C [2] (2A): 10.0 g of Fe at 2 deg C or (2B): 10.0 g of Fe at 35 deg C [3] (3A): 25 L of air at 1 atm pressure or (3B): 25 L of air compressed isothermally to 100 atm pressure A: 1A, 2A, 3A B: 1B, 2A, 3B C: 1A, 2B, 3A D: 1B, 2B, 3B

Answer 38

D: 1B, 2B, 3B

Question 39

An aqueous solution of mannitol in water has a vapor pressure of 17.504 mmHg at 20oC, at which temperature, the vapor pressure of pure water is 17.535 mmHg. What is the freezing point depression of the solution? A: 0.186°C B: 0.194°C C: 0.211°C D: 0.237°C

Answer 39

A: 0.186°C

Question 40

A solution of 3.795 g of sulfur in 100 g of carbon disulfide (Boiling Point = 46.3 deg C) boils at 46.66 deg C. What is the formula of the sulfur molecule in the solution? Use an ebullioscopic constant of 2.42 for carbon disulfide. A: S2 B: S4 C: S6 D: S8

Answer 40

D: S8

Question 41

1000 g of a 1 molal aqueous solution of sucrose is cooled and maintained at a temperature of -3.534 deg C. How much ice, do you approximate, will separate out from the solution? A: Less than 200 g B: Between 300 to 500 g C: greater than 700 g D: Inefficient amount of information

Answer 41

B: Between 300 to 500 g

Question 42

A chef from Makati specializing in molecular gastronomy decided to perform an experiment for fun. He bought a red balloon filled with air and poured liquid nitrogen over it. What will happen to the pressure inside the balloon? A: It increases B: It decreases C: Remains the same D: Not enough info

Answer 42

B: It decreases

Question 43

A laboratory analysis requires mixing a variety of solutions. One solution requires mixing 3.00 L of 0.92 M Copper (II) Nitrate with 7.00 L of an unknown concentration of Sodium Hydroxide while a separate solution is prepared by mixing 2.00 M of Potassium Hydroxide and 12.0 M Oxalic Acid. What are the states of the Copper(II) Hydroxide and Potassium Oxalate produced? A: Cu(OH)2 and K2C2O4 are both solids. B: Cu(OH)2 is a liquid while K2C2O4 is a gas. C: Cu(OH)2 is a gas while K2C2O4 is a solid. D: Cu(OH)2 is a solid while K2C2O4 is a liquid.

Answer 43

D: Cu(OH)2 is a solid while K2C2O4 is a liquid.

Question 44

Several pints of blood were collected during a Red Cross Program across several universities in Manila. From those collected, a peroxidase enzyme was isolated from a human red blood cell. Performing a quick analysis shows that it contained 0.29% of Selenium. What is the minimum molecular weight of the enzyme? A: 2.31x10^5 B: 2.75x10^4 C: 3.10x10^6 D: 5.88x10^8

Answer 44

B: 2.75x10^4

Question 45

Which among the following third gas that William Ramsay with Morris Travers? A: Argon B: Neon C: Krypton D: Xenon

Answer 45

D: Xenon 1st Neon, 2nd Krypton

Question 46

How many carbon atoms are there in one molecule of “buckyball”? A: 20 B: 40 C: 60 D: 80

Answer 46

C: 60

Question 47

Determine which particles are being described by each of the following statements: [a.] Has the greatest penetrative capability [b.] Sometimes called as the positive electron [c] Contact with it can cause the greatest biological destruction [d] Cannot be affected by a magnetic field A: Alpha Particles, Beta Particles, Gamma Rays, Positron B: Gamma Rays, Positron, Alpha Particles, Gamma Rays C: Beta Particles, Neutrino, Alpha Particles, Beta Particles D: Neutrino, Positron, Gamma Rays, Beta Particles

Answer 47

B: Gamma Rays, Positron, Alpha Particles, Gamma Rays

Question 48

Which among the following scientists discovered radioactivity? A: Marie Curie B: Henri Becquerel C: Otto Hahn D: Ernest Rutherford

Answer 48

B: Henri Becquerel

Question 49

For a criminal case, two men are interrogated in regards to an attempted poisoning of a police officer. During the investigation, it was found out that both men had traces of Polonium-210 on their hands while a third accomplice of theirs had Po-210 on his clothes. Through analysis of the police officers stomach content, it was confirmed that he had ingested Po-210. Which among them is/are bound to die if not properly treated? A: The police officer only B: The two men and the third accomplice C: The police officer and the two men D: All four of them

Answer 49

A: The police officer only

Question 50

Fill in the blank: Protium is a/an ______ of Hydrogen while Protium, Deuterium, and Tritium comprise the Hydrogen _______. A: Isotope, Isotopes B: Nuclide, Nuclides C: Nuclide, Isotopes D: Isotope, Nuclides

Answer 50

C: Nuclide, Isotopes

Question 51

Which among the following radioactive decay series does not occur naturally? A: Actinium Series B: Uranium Series C: Neptunium Series D: Thorium Series

Answer 51

C: Neptunium Series Also artificial: Plutonium Series

Question 52

To which decay series does Rn-219 and Ac-225 belong to respectively? A: Actinium Series and Plutonium Series B: Uranium Series and Actinium Series C: Thorium Series and Uranium Series D: Plutonium Series and Thorium Series

Answer 52

A: Actinium Series and Plutonium Series

Question 53

Which among the following statements regarding Sb-122 and Xe-136 is TRUE? A: Sb-122 is more stable than Xe-136 because of its atomic number B: Xe-136 and Sb-122 are radioactive C: Xe-136 is more stable than Sb-122 because of the amount of its neutrons D: Sb-122 and Xe-136 are both stable

Answer 53

C: Xe-136 is more stable than Sb-122 because of the amount of its neutrons

Question 54

Determine whether each of the following statements is True or False [a]: Calcium-42 is more abundant in natural sources in comparison to Calcium40 [b.] Phosphorus-29 undergoes beta particle emission in order to become more stable [c.] Potassium-45, a radioactive nuclide, undergoes positron emission in order to reach a new level of stability A: True,True,True B: False,True,True C: True,False,False D: False,False,False

Answer 54

D: False,False,False

Question 55

Which among the following can detect the neutrons produced by U-235 undergoing nuclear fission? A. A Geiger Counter containing Fluorine Gas B. A Scintillation Counter containing Zinc Sulfide and Xenon C: A Geiger Counter containing Argon and Boron trifluoride D: A Scintillation Counter containing Tungsten Carbide

Answer 55

C: A Geiger Counter containing Argon and Boron trifluoride

Question 56

Which among the following is the phosphor of a scintillation counter intended for the detection of gamma radiation? A: Zinc Sulfide B: Metastable Technetium-99 C: NaI Crystals containing Thallium (II) Iodide D: Buckminsterfullerene

Answer 56

C: NaI Crystals containing Thallium (II) Iodide

Question 57

A sample of Pitchblende from Bataan is being analyzed for its age. For this analysis, the amounts of Uranium-238 and Lead-206 were determined. If the results show that nuclides mass ratio is 0.2:1 for the U-238:Pb-206. What is the age of the mineral? Assume a half-life of 4.5x10^9 years for the process. A: 1.35x10^9 yrs B: 1.62x10^9 yrs C: 1.73x10^9 yrs D: 1.89x10^9 yrs

Answer 57

A: 1.35x10^9 yrs

Question 58

Determine the age of a mineral sample which contains 50.05 mg of 238-Uranium and 14.05 mg of 206-Lead. Assume a half life for the process of 238-U and 206-Pb at 4.52x10^9 years. A: K = 1.50x10^-10 per year; 75.2 mg 238 U; 2.20x10^9 years old B: K = 1.80x10^-9 per year; 66.2 mg 238 U; 1.80x10^9 years old C: K = 0.90X10^-8 per year; 56.1 mg 238 U; 1.30X10^9 years old C: K = 2.10X10^-9 per year; 87.1 mg 238 U; 2.80X10^9 years old

Answer 58

B: K = 1.80x10^-9 per year; 66.2 mg 238 U; 1.80x10^9 years old

Question 59

Define atomic mass unit. A: The mass of one Carbon-12 atom B: One half the mass of a carbon-14 mole C: One-twelfth the mass of a Carbon-12 atom D: One-twelfth the mass of 6.022x10^23 atoms of Carbon-14

Answer 59

C: One-twelfth the mass of a Carbon-12 atom

Question 60

Determine the binding energy per nucleon involved in the formation of a single silver-107 atom. The measured mass of the nuclide in question is 106.879289 atomic mass units. A: 4.51 MeV/nucleon B: 6.33 MeV/nucleon C: 8.58 MeV/nucleon D: 9.61 MeV/nucleon

Answer 60

C: 8.58 MeV/nucleon

Question 61

Based on the units commonly used in Nuclear Chemistry, which among the following measures the amount of energy acquired by an electron when it falls through an electric potential difference of 1 volt? A: Ci B: Bq C: eV D: Gy

Answer 61

C: eV

Question 62

Which among the following can cause the greatest damage to a material assuming that all of them can penetrate it equally? A: 100 rad Gamma rays B: 100 rad Beta Emission C: 100 rad Neutron Emission D: 100 rad Alpha Emission

Answer 62

D: 100 rad Alpha Emission

Question 63

Which among the following statements regarding Nuclear Fusion and Nuclear Fission is False? A: Nuclear fusion involves the amalgamation of lighter nuclei in order to form heavier, stabler nuclei B: The maximum binding energy per nucleon can be achieved at a mass number of 60 C: Nuclear fusion releases more energy than Nuclear fission on a per nucleon basis D: The fragmentation of heavier nuclides displays a relatively plateau decrease in binding energy when compared to the reverse

Answer 63

C: Nuclear fusion releases more energy than Nuclear fission on a per nucleon basis

Question 64

In which among the following can a Cherenkov Radiation be observed? A: In the Water surrounding the core of a Nuclear Reactor B: In the Mushroom Cloud produced after a Hydrogen Bomb Explosion C: In a particle accelerator after the bombardment of two nuclides D: In the Sun’s Corona during a Solar Eclipse

Answer 64

A: In the Water surrounding the core of a Nuclear Reactor

Question 65

The Bataan Nuclear Power Plant is planned to be retrofitted in hopes of using it for the first time. One point of concern is the material that would be used in the outer portions of the room housing the fuel rods. If the radiation coming from the fuel rods would be a strong beta emission, which material among the following should be utilized? A: 1.00 cm of Aluminum B: 7.50 m of Concrete C: 8.0 mm of Lucite D: 35.0 m of Lead

Answer 65

C: 8.0 mm of Lucite

Question 66

Across the three most notorious accidents regarding nuclear power plants: Three Mile Island, Chernobyl, and Fukushima, what is the most common cause for their failure that led to several environmental problems? A: A leak in the fuel rods initiating an explosion B: Bursting of reactor due to uncontrolled pressurized steam C: Loss of proper cooling and/or moderator D: Run-off chain reactions of the fissile material

Answer 66

C: Loss of proper cooling and/or moderator

Question 67

Which among the following statements regarding Nuclear Fission is FALSE? A: Nuclear Fission is a nuclear reaction in which a heavy nucleus splits into lighter nucleus and energy is released B: A series of self-sustaining nuclear fissions is called a nuclear chain reaction C: Nuclear Fission is the main proponent of nuclear power plants, atomic bombs, and hydrogen bombs D: Critical mass is the minimum amount of a fissionable material that can cause a nuclear chain reaction

Answer 67

C: Nuclear Fission is the main proponent of nuclear power plants, atomic bombs, and hydrogen bombs Hydrogen bombs are nuclear fusion

Question 68

Which among the following radioactive nuclides is often attributed as the greatest source of radiation that affects most of the population? A: Strontium-90 B: Americium-241 C: Polonium-218 D: Radon-222

Answer 68

D: Radon-222

Question 69

Which among the following radioactive nuclides is used as a radioactive tracer for agricultural crops and eye disease treatments A: Strontium-90 B: Americium-241 C: Polonium-218 D: Radon-222

Answer 69

A: Strontium-90

Question 70

Which among the following radioactive nuclides is used in smoke detectors A: Strontium-90 B: Americium-241 C: Polonium-218 D: Radon-222

Answer 70

B: Americium-241

Question 71

A nuclear chemist from the Philippine Nuclear Research Institute is dissolving a sample of NaCl, that contains the radioactive sodium-24, in 100 mL aliquot of aqueous sodium nitrate. The mixture was subsequently cooled in order to recrystallize the sodium nitrate salt. Which among the following is true? A: The chloride anions will selectively reform an ionic bond with the sodium-24 cation B: The sodium nitrate crystals should be non-radioactive C: All of the sodium-24 cations would specifically bond with the nitrate ion due to its electron-distribution capability D: Some of the anions will randomly bond with the sodium-24 nuclide

Answer 71

D: Some of the anions will randomly bond with the sodium-24 nuclide

Question 72

Actinium-227 can decay into two nuclides. One forming Thorium-227 and the other as Francium-223. With respect to radioactive decay, the half life of Ac227 is 21.8 years. If the fractional yield of Th-227 and Fr-223 is 0.012 and 0.988 respectively, what is the decay rate constant for each of the respective paths leading to the daughter nuclides? A: 3.82x10^-4 per year; 0.0314 per year B: 4.12x10^-4 per year; 0.0172 per year C: 2.75x10^-5 per year; 0.1221 per year D: 6.92x10^-5 per year; 0.0719 per year

Answer 72

A: 3.82x10^-4 per year; 0.0314 per year

Question 73

A 1.0 g sample of microline (KAlSi3O8), containing K-40, was allowed to undergo radioactive decay. Based on literature data, 89% of the nuclide undergoes beta particle emission while the remainder undergoes electron capture and positron emission. How many beta particles are produced per second if the percent natural abundance of the concerned nuclide is 0.0117%. The half life of K-40 is 1.26x10^9 years. A: 4.0 B: 8.0 C: 12.0 D: 16.0

Answer 73

A: 4.0

Question 74

Friedrich Wohlers work on isomerism was able to curb the growth of vitalism by disproving the old notion that organic compounds can only come from organic sources. Which among the following was the product produced in Wohler’s synthesis? A: Ammonium Cyanate B: Urea C: Carbon Disulfide D: Acetic Acid

Answer 74

B: Urea

Question 75

What did Jons Jacob Berzelius contribute? A. Synthesis of Urea B. Experiment on Isomerism C. Conversion of Acetic Acid D. Production of Ammonium Cyanate

Answer 75

B. Experiment on Isomerism

Question 76

Who first converted carbon disulfide into acetic acid? A. Jons Jacob Berzelius B. Friedrich Wohler C. Adolph Wilhelm Hermann Kolbe D. August Kukule

Answer 76

C. Adolph Wilhelm Hermann Kolbe

Question 77

Who among the following constituted the concept of resonance in order to take explain the structures of molecules or ions that are not accounted for by the octet rule? A: August Kekule B: Linus Pauling C: Gilbert Lewis D: Robert Robinson

Answer 77

B: Linus Pauling

Question 78

Which among the following statements highlights the actual difference between Lewis Structures and Resonance A: Lewis structures shows how the atoms of a molecule are bonded to one another while the resonance represents the different substituent combinations B: Lewis structures focuses on the localization of electrons while resonance features the electrons capacity of being delocalized among the atoms C: Resonance structures represent the various ways in which a molecule can be drawn while the Lewis structure represents the accepted “True” structure of the molecule D: A resonance structure and Lewis structure are virtually indistinguishable from one another

Answer 78

B: Lewis structures focuses on the localization of electrons while resonance features the electrons capacity of being delocalized among the atoms

Question 79

Determine whether each of the following statements pertaining to constitutional isomers is TRUE or FALSE. [a.] They have the same molecular formula [b.] They have the same molecular weight [c.] They have the same connectivity to their atoms [d.] They have the same physical properties A: T, F, F, F B: T, T, F, F C: F, T, T, T D: T, F, T, F

Answer 79

B: T, T, F, F

Question 80

Explain the difference in structure between a saturated hydrocarbon from an unsaturated hydrocarbon. A: Any of these B: A saturated hydrocarbon only contains carbon-carbon single bonds while an unsaturated hydrocarbon contains one or more carbon-carbon double or triple bonds C: A saturated hydrocarbon is used mainly in cheaper forms of gasolines for vehicle use while unsaturated hydrocarbons compose most of the gasoline formulae used by current gasoline manufacturers D: A saturated hydrocarbon can no longer accept any hydrocarbon or inorganic element, and compound while an unsaturated hydrocarbon is more flexible in reaction mechanisms

Answer 80

B: A saturated hydrocarbon only contains carbon-carbon single bonds while an unsaturated hydrocarbon contains one or more carbon-carbon double or triple bonds

Question 81

Which among the following can be the possible structures of a molecule that has the molecular formula C5H8? A: Alkane and Alkene with a single double bond B: Alkene with a single double bond and Alkyne with a single triple bond C: Cycloalkane and an Alkene with two double bonds D: Cycloalkene with a single double bond and two rings

Answer 81

B: Alkene with a single double bond and Alkyne with a single triple bond

Question 82

An entomologist extracted pheromone samples from a moth captured in the wilds of Maguindanao. Based on a spectroscopic analysis, the molecule is a 2-methyl branched alkane. If it has a molecular weight of 254, what is the IUPAC name of the alkane? A: 2,3-dimethylhexadecane B: 2-methylheptadecane C: 2,2,4-trimethylpentadecane D: 2-methyloctadecane

Answer 82

B: 2-methylheptadecane

Question 83

For each of the following organic molecules, determine which one is more stable relative to the other. [a] Hexane or Octane [b] 2-methylpentane or 2,2-dimethylpropane [c] 3-methylpentane or 3,3-dimethylpentane A: Hexane, 2,2-dimethylpropane, 3-methylpentane B: Octane, 2-methylpentane, 3-methylpentane C: Octane, 2,2-dimethylpropane, 3,3-dimethylpentane D: Hexane, 2-methylpentane, 3,3-dimethylpentane

Answer 83

A: Hexane, 2,2-dimethylpropane, 3-methylpentane

Question 83

Which among the following molecules is an improperly named consitutional isomer of the compound: 2,3-dimethylpentane? A: 3-ethylpentane B: 3,4-dimenthlypentane C: heptane D: 2,2,3-trimethylbutane

Answer 83

B: 3,4-dimenthlypentane

Question 84

Which has a higher absolute entropy at a temperature of 25 deg C, cyclopropane or propylene? Why? A: Both have the same absolute entropy at normal temperature B: Propylene due to the free rotation around the carbon-carbon single bond C: Cyclopropane due to the free rotation around the carbon-carbon double bond D: None of these

Answer 84

B: Propylene due to the free rotation around the carbon-carbon single bond

Question 85

Fatty acid such as lauric acid, palmitic acid, and oleic acid are long unbranched carboxylic acids consisting of 12 to 20 carbon atoms. Which type of fatty acid should people avoid ingesting, saturated or unsaturated and why? A. Saturated, because the risk of cardiovascular disease is increased B. Fatty Acids are safe to ingest C. Unsaturated because the risk of cardiovascular disease is increased D. Both fatty acids because the risk of cardiovascular disease is increased

Answer 85

A. Saturated, because the risk of cardiovascular disease is increased

Question 85

Which among the following statements is true regarding the boiling point and density of an unsubstituted alkane and a halogen-substituted alkane? A:Both the boiling point and density of a halogen-substituted alkane is larger than that of its unsubstituted alkane counterpart. B: Both the boiling point and density of an unsubstituted alkane is larger than that of its halogen-substituted alkane counterpart. C: The boiling point of an unsubstituted alkane is larger than its halogen substituted counterpart but their density are equal. D: The density of a halogen substituted alkane is larger than that of its unsubstituted alkane counterpart but their boiling points are the same.

Answer 85

A:Both the boiling point and density of a halogen-substituted alkane is larger than that of its unsubstituted alkane counterpart.

Question 86

Which among the following compounds will rapidly react with hydrogen bromide in order to form its corresponding alkyl bromide? A: 2-methylbutane B: 2-butanol C: Cyclohexanol D: 1-ethylcyclopentanol

Answer 86

D: 1-ethylcyclopentanol

Question 87

How is a carbocation stabilized by the alkyl groups attached to it? A: The alkyl groups release an electron density on the positively charged carbon in order to disperse the positive charge B: The electrons that are sigma to the positively charged carbon has its orbital overlap with the vacant p orbital of the positively charged carbon C: The leaving group transfers some of its electrons to the carbocation in order to disperse the positive charge D: The electrons in the alpha-Carbon hydrogen bonds greatly distributes the positive charge as opposed to the betacarbon hydrogen bonds

Answer 87

A: The alkyl groups release an electron density on the positively charged carbon in order to disperse the positive charge

Question 88

Rearrange the following alkenes the order of increasing stability: [a] 2,4-dimethyl-1-pentene [b] 2,4,4-trimethyl-2-pentene [c] 2,4-dimethyl-2-pentene [d] (Z)-4,4-dimethyl-2-pentene A: B < D < A < C B: C < B < D < A C: D < A < C < B D: A < D < B < C

Answer 88

A: B < D < A < C

Question 89

Which among the following organic compounds will be produced when 2,4-dimethyl-3-pentanol is heated to 120 deg C in the presence of sulfuric acid? A: 2,4-dimethyl-1 pentene B: 2,4-dimethyl-2-pentene C: Both A and B D: Neither A and B

Answer 89

C: Both A and B

Question 90

Which among the following reagents will not synthesize cyclohexanol if the starting material is cyclohexene? A: [1] Diborane, [2] Hydrogen Peroxide, Sodium Hydroxide B: Bromine and Water C: Water with Sulfuric Acid D: [1] 9-BBN, [2] Basic Hydrogen Peroxide

Answer 90

B: Bromine and Water

Question 91

23. A chemical engineering student is studying the reaction mechanism of a certain compound V. In one of the runs, compound V was dissolved in methanol and subsequently reacted with ozone, forming compound W. Compound W later underwent reduction through a reaction with dimethyl sulfide forming Acetone and Acetaldehyde. Identify Compound V. A: 3-methyl-2-butene B: 2-methyl-1-butene C: 3-methyl-1-butene D: 2-methyl-2-butene

Answer 91

D: 2-methyl-2-butene

Question 92

Who among the following proposed the idea correlating Molecular Geometry and Valence Electron Pairs that would later become the Valence Shell Electron Pair Repulsion (VSEPR) Theory? A: Nevil Sidgwick B: Ronald Nyholm C: Herbert Powell D: Ryutaro Tsuchida

Answer 92

B: Ronald Nyholm

Question 93

What is the electron-group geometry of CO2, H2S, and XeF4? A: Linear, Tetrahedral, Octahedral B: Tetrahedral, Octahedral, Trigonal bipyramidal C: Linear, Trigonal Planar, Octahedral D: Octahedral, Trigonal bipyramidal, Tetrahedral

Answer 93

A: Linear, Tetrahedral, Octahedral

Question 94

What is the molecular geometry of CO2, H2S, and XeF4? A: Linear, Seesaw, Square Pyramidal B: Bent, Tetrahedral, T-shaped C: Linear, Bent, Square Planar D: Octahedral, Square Planar, Seesaw

Answer 94

C: Linear, Bent, Square Planar

Question 95

What is the hybridization scheme for the central atom of NO3^-1? A: sp2 B: sp3 C: sp3d D: sp3d2

Answer 95

A: sp2

Question 96

Linus Pauling introduced the concept of hybridization of orbitals in order to take into account the known geometries of certain compounds, which did not include ____. A: H2O B: NH3 C: CH4 D: H2S

Answer 96

D: H2S

Question 97

What is the Nujol Mull in organic chemical reactions? A: It is a mass spectrum technique and is obtained by grinding up a solid which is mixed with mineral oil to form a suspension for IR spectroscopy B: It is the name of a type of paraffin oil from India and most often used in gas chromatography to enhance the mass transfer properties of compounds C: It is a process applied for inorganic compounds to determine the effervescence of the compound under study D: It is suspension in mineral oil which is placed in between HgCl, AgI, and KCl, or stainless-steel plates to obtain a good spectrum.

Answer 97

A: It is a mass spectrum technique and is obtained by grinding up a solid which is mixed with mineral oil to form a suspension for IR spectroscopy

Question 98

What are sigmatropic rearrangements in organic reactions? A: They are similar to the (3,3) cope rearrangement where the beta ring of a steroid undergoes photon activated retroelectrocyclization B: They are thermal reactions which do not allow the formation of six membered benzene ring with a cis or trans alkene such as in the formation of Vitamin D3 C: They are different from electrolytic reactions wherein movement of a sigma bond with a simultaneous rearrangement of the pi-system does not occur D: They are not the same to the (3,3) cope arrangement and the beta ring does not undergo photon activated retro electrocyclization

Answer 98

A: They are similar to the (3,3) cope rearrangement where the beta ring of a steroid undergoes photon activated retroelectrocyclization

Question 99

An ideal gas will only be considered in the following operating parameters: a. High Temperature, High Pressure b. High Temperature, Low Pressure c. Low Temperature, High Pressure d. Low Temperature, Low Pressure

Answer 99

b. High Temperature, Low Pressure

Question 100

Which ofthe following isfalse regarding absolute zero? a. All molecules will stop moving b. Absolute zero can be achieved c. Temperature is 0K d. Temperature is 0R

Answer 100

b. Absolute zero can be achieved

Question 101

For a real gas, what causes the deviation from the ideal pressure at a molecular level? a. Energy is lost for each collision against the sides of the container b. Energy is lost due to the collision of molecules with one another c. Intermolecular forces of attraction of the molecules with one another d. Molecules randomly hit the sides of the wall with less force than usual

Answer 101

c. Intermolecular forces of attraction of the molecules with one another

Question 102

When gas molecules collide, they experience ____ collision. a. Perfectly elastic b. Imperfect elastic c. Perfectly inelastic d. Imperfect inelastic

Answer 102

a. Perfectly elastic

Question 103

Which of the following is false with KMT? a. Gas molecules move in random motion b. Due to collision of gas molecules with each other, some kinetic energy is lost c. The temperature of the whole system does not change with time d. The size of the molecules are negligible

Answer 103

b. Due to collision of gas molecules with each other, some kinetic energy is lost

Question 104

This is the pressure exerted by the gas molecules that are in equilibrium with the liquid. a. Partial pressure b. Atmospheric pressure c. Total pressure d. Vapor pressure

Answer 104

d. Vapor pressure

Question 105

The internal energy of an ideal gas depends on: a. Volume b. Absolute temperature c. Pressure d. Number of moles

Answer 105

b. Absolute temperature

Question 106

The state of an ideal gas is changed in a closed path 1→2→3→4→1. Which of the following is true about the work done on the gas? a. W12>0, W23=0, W34<0, W41=0 b. W12<0, W23=0, W34=0, W41>0 c. W12=0, W23>0, W34=0, W41<0 d. W12=0, W23<0, W34=0, W41>0

Answer 106

d. W12=0, W23<0, W34=0, W41>0

Question 107

Which of the following is a characteristic of an adiabatic process? a. ΔU=0 b. W=0 c. Q=0 d. ΔV=0

Answer 107

c. Q=0

Question 108

A sample of an ideal gas has an internal energy of U and is then compressed to 1⁄2 of its original volume while the temperature stays the same. What is the new internal energy of the ideal gas in terms of U? a. U b. U/2 c. U/4 d. 2U

Answer 108

a. U

Question 109

Which of the following is not conserved in any process? a. Mass b. Energy c. Momentum d. Entropy

Answer 109

d. Entropy

Question 110

An isentropic process is: a. Isothermal and adiabatic b. Reversible and isothermal c. Reversible and adiabatic d. Reversible and isochoric

Answer 110

c. Reversible and adiabatic

Question 111

Increasing the temperature of the cold reservoir _____ the Carnot efficiency. a. Increases b. Decreases c. Does not change d. NOTA

Answer 111

b. Decreases

Question 112

If the entropy of a system decreases, the entropy of its surroundings a. Must always increase b. Must always decrease c. May increase or decrease d. Not enough information to answer the question

Answer 112

a. Must always increase

Question 113

Which of the following is not true? A. (∂G/∂P)_T = V B. (∂H/∂P)_T = V C. (∂G/∂T)_P = -S D. (∂H/∂V)_T = -S

Answer 113

D. (∂H/∂V)_T = -S

Question 114

Which of the following is not true? A. (∂G/∂P)_T = V B. (∂G/∂T)_P = -S C. (∂H/∂P)_S = V D. (∂A/∂V)_T = -S

Answer 114

D. (∂A/∂V)_T = -S should be (∂A/∂V)_T = P

Question 115

Which of the following is true? A. (∂T/∂V)_S = (∂P/∂S)_V B. (∂P/∂T)_V = -(∂S/∂V)_T C. (∂T/∂P)_S = (∂V/∂S)_P D. (∂V/∂T)_S = (∂D/∂P)_T

Answer 115

C. (∂T/∂P)_S = (∂V/∂S)_P

Question 116

Enthalpy can be expressed as a function of T and P. This relationship is shown by: A. dH = CpdT + [V - T(∂V/∂T)_P]dP B. dH = CpdT + [P - T(∂P/∂T)_V]dP C. dH = CpdT + [T(∂V/∂T)_P - V]dP C. dH = CpdT + [T(∂P/∂T)_V - P]dP

Answer 116

A. dH = CpdT + [V - T(∂V/∂T)_P]dP

Question 117

The amount of heat absorbed when CO2 gas reacts with a solid CaO to form solid CaCO3 is measured in a bomb calorimeter. The data obtained give a direct measure of: a. ΔU b. VΔP c. ΔH d. CP

Answer 117

a. ΔU

Question 118

Heat required to raise the temperature of 1lbm of water by 1 ̊F. a. Calorie b. BTU c. Specific heat d. Heat capacity

Answer 118

b. BTU

Question 119

Which of the following statements is/are true? 1. The criterion of equilibrium at constant temperature and pressure is dG=0. 2. For a reversible process, dS=dQ/T. a. 1 only b. Both 1 and 2 c. 2 only d. None of the above

Answer 119

b. Both 1 and 2

Question 120

The general statement of the Third Law of Thermodynamics is attributed to: a. Nikolaus Otto b. Jacobus Clapeyron c. William Clausius d. Walther Nernst

Answer 120

d. Walther Nernst

Question 121

The general statement of the Zeroth Law of Thermodynamics is attributed to: a. Ralph Howard Fowler b. Walther Nernst c. Rudolf Emmanuel Clausius d. William Clausius

Answer 121

a. Ralph Howard Fowler

Question 122

The general statement of the First and Second Law of Thermodynamics is attributed to: a. Ralph Howard Fowler b. Walther Nernst c. Rudolf Emmanuel Clausius d. William Clausius

Answer 122

c. Rudolf Emmanuel Clausius

Question 123

The equilibrium intensive state of a system is described by specifying the temperature, pressure, and: a. Mole fractions b. Number of moles c. Volume d. Chemical potential

Answer 123

a. Mole fractions

Question 124

The fugacity of a real gas is equal to: a. The pressure of an ideal gas which has the same chemical potential as the real gas b. The pressure of a real gas which has the same chemical potential as the ideal gas c. The chemical potential of an ideal gas which has the same pressure as the real gas d. The chemical potential of a real gas which has the same pressure as the ideal gas

Answer 124

a. The pressure of an ideal gas which has the same chemical potential as the real gas

Question 125

An adiabatic process is one in which the system under investigation is thermally isolated so that there is no exchange of heat with the surroundings. Thus, the work done on a closed system in an adiabatic process is _____. a. Equal to zero b. Not equal to the exchange of heat with surroundings c. Equal to the increase in internal energy of the system d. Not equal to the increase in internal energy of the system

Answer 125

c. Equal to the increase in internal energy of the system

Question 126

If enthalpy is defined as present in a constant pressure process change of state, using the relationship of ΔH=ΔU+ΔPV, where H is enthalpy, U is the energy change in the system and PV represents pressure and volume states, determine the ΔU and ΔH of 1kg of water when vaporized at constant temperature of 100 ̊C and constant pressure of 101.35kPa. The specific volumes of liquid and vapor water are 0.001041 and 1.67m3/kg. An amount of 2257kJ of heat is added to the water. a. ΔU=2087kJ; ΔH=2257kJ b. ΔU=2378kJ; ΔH=2221kJ c. ΔU=2226kJ, ΔH=2378kJ d. None of these

Answer 126

a. ΔU=2087kJ; ΔH=2257kJ

Question 127

A certain gas confined in a cylinder by a piston, where the initial pressure in the system is 7 bar and the volume is 0.11 cubic meter. The piston is held in place by latches and the apparatus is in vacuum. Determine the change in energy when the latches are removed suddenly and the gas expands to double its initial volume and the piston strikes the latches at the end of the process. a. 11.54kJ b. 0.77kJ c. 0.59kJ d. No change

Answer 127

d. No change

Question 128

State Le Chatelier’s Principle. a. Le Chatelier’s principle states that when a stress is placed on a system in equilibrium, the system tends to change in a way that relieves the stress. b. All of these c. Examples of the application of Le Chatelier’s principle are blowing your breath through a straw and dissolving alka seltzer tablet in a glass of water. d. Le Chatelier’s principle explains both the formation and decomposition of acids, where anything that might act to increase the concentration of an acid would produce an increase in the other components so as to keep the numerical

Answer 128

a. Le Chatelier’s principle states that when a stress is placed on a system in equilibrium, the system tends to change in a way that relieves the stress.

Question 129

Determine which of the following occurrences tells us what happens when Le Chatelier’s principle is applied whether these are true or false. 1. The addition of a component causes the equilibrium to shift to the opposite side 2. The removal of a component causes the equilibrium to the side from which the component is removed 3. Increasing the temperature drives an exothermic reaction to the side of the reactants, an endothermic equilibrium to the side of the products 4. The addition of a catalyst has NO effect on the position of the equilibrium a. T, F, T, F b. T, T, T, T c. F, T, F, T d. F, F, F, F

Answer 129

b. T, T, T, T

Question 130

Define entropy. a. Entropy is a function of the state of the system and determines whether a physical change or chemical reaction can occur simultaneously in a closed system b. Entropy is the opposite of enthalpy c. Entropy determines the time required for a reaction to proceed and complete d. All of these

Answer 130

d. All of these

Question 131

Determine whether the changes in entropy (ΔS) and enthalpy (ΔH) are positive, negative, or near zero. 1. Ethyl alcohol evaporating from glass container 2. A diatomic molecule dissociates into atoms 3. Charcoal is burned to form CO2 and water a. 1. ΔH>0, ΔS>0; 2. ΔH>0, ΔS>0; 3. ΔH>0, ΔS>0 b. 1. ΔH<0, ΔS<0; 2. ΔH>0, ΔS<0; 3. ΔH>0, ΔS<0 c. 1. ΔH>0, ΔS<0; 2. ΔH<0, ΔS>0; 3. ΔH>0, ΔS>0 d. 1. ΔH<0, ΔS>0; 2. ΔH<0, ΔS<0; 3. ΔH<0, ΔS<0

Answer 131

a. 1. ΔH>0, ΔS>0; 2. ΔH>0, ΔS>0; 3. ΔH>0, ΔS>0

Question 132

Choose the process that occurs with a decrease in entropy. a. Freezing of water b. Boiling of water c. Dissolving salt in water d. Sublimation of dry ice

Answer 132

a. Freezing of water

Question 133

A vessel of volume 22.4dm3 contains 2mol H2 and 1mol N2 at 273.15K. What is the total pressure inside the vessel? Assume ideal gas. a. 1atm b. 2atm c. 3atm d. 4atm

Answer 133

c. 3atm

Question 134

Applying the combined gas laws, determine the volume of 1mol of Ne(g) in a flask at the temperature of 25 ̊C and a pressure of 1atm. a. 12.2L b. 18.6L c. 32.21L d. 24.51L

Answer 134

d. 24.51L

Question 135

In the combustion of 25g of methane gas, what is the volume of oxygen required at 25 ̊C and 0.21atm? a. 411 b. 298 c. 363 d. 521

Answer 135

c. 363

Question 136

Determine the volume of carbon dioxide in cubic feet occupied by 120lb at a pressure of 1.5atm. (T=40 ̊C) a. 750 b. 490 c. 560 d. 680

Answer 136

a. 750

Question 137

If 1mol of an ideal gas is kept at 0 ̊C, during an expansion from 3.0 to 10.0L, examine and calculate how much work is done as the gas during expansion. a. -2.2x10^4J b. -5.4x10^3J c. -7.8x10^4J d. -2.7x10^3J

Answer 137

d. -2.7x10^3J

Question 138

In a gas mixture containing 100mg/L of H2S gas at 25 ̊C and 1atm, determine the partial pressure exerted by the gas. a. 0.071 b. 0.003 c. 0.101 d. 0.006

Answer 138

a. 0.071

Question 139

Which of the following does not have a zero enthalpy of formation at 298.15K? a. Li(g) b. He(g) c. Hg(l) d. Br2(l)

Answer 139

a. Li(g)

Question 140

Calculate the net and the gross heats of combustion for methane gas. a.-491kJ; -998kJ/mol b.-362kJ; -731kJ/mol c.-891kJ/mol; -802kJ/mol d.-598kJ; -1120kJ/mol

Answer 140

c.-891kJ/mol; -802kJ/mol Perry’s T-179

Question 141

If 5g of methane gas is burned at constant pressure, determine the heat released in kJ if the change in entropy that accompanied the reaction is -890kJ. a. -360.00K b. -250.01K c. -278.12K d. -192.00K

Answer 141

c. -278.12K

Question 142

The standard molar enthalpy change is -905kJ for the oxidation of ammonia, 4NH3(g)+5O2→4NO(g)+6H2O(g). Analyze and calculate the standard molar enthalpy of formation for ammonia based on the following standard enthalpies of formation: HF[NO(g)]=+90kJ/mol; and HF[H2O(g)]=-240kJ/mol a. -227kJ/mol b. -500kJ/mol c. -406kJ/mol d. -692kJ/mol

Answer 142

a. -227kJ/mol

Question 143

It is the property of a fluid that is caused by shearing effect of a fluid layer moving past another layer. a. Density b. Viscosity c. Flow d. Compressibility

Answer 143

b. Viscosity

Question 144

The Clapeyron Equation gives the slope: a.dV/dT b.dT/dP c.dT/dV d.dP/dT

Answer 144

d.dP/dT

Question 145

The Clausius-Clapeyron Equation does NOT apply to: a. S-V equilibrium b. L-V equilibrium c. S-L equilibrium d. None of these

Answer 145

c. S-L equilibrium

Question 146

What is the Clapeyron Equation? a. Any of these b. It postulates that the colligative properties, freezing point depression, boiling point elevation, osmotic pressure, and vapor pressures are all dependent on the number f particles in the solution and any change thereof is described. c. It postulates that if two components systems consisting of solid and liquid phases are miscible in the liquid state and immiscible in the solid state, only the pure solid systems will separate out on cooling solutions. d. It postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.

Answer 146

d. It postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.

Question 147

The coexistence curve where the plot of pressure versus temperature along which the two phases coexist was shown by Clausius-Clapeyron. What did Clausius postulate? a. The Clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molar volume of the liquid VL in comparison with the molar volume of the gas VG b. The Clausius-Clapeyron equation does not apply to this situation c. The Clausius-Clapeyron theory is applicable only for vaporization and sublimation condition d. Both scientists apply their postulates to linear and curvilinear representation

Answer 147

a. The Clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molar volume of the liquid VL in comparison with the molar volume of the gas VG

Question 148

For miscible systems, the boiling point of the solution is: a. Lower than the boiling point of the liquid with the lower boiling point b. Between the boiling points of the two liquids c. Above the boiling point of the liquid with the higher boiling point d. Cannot be determined

Answer 148

b. Between the boiling points of the two liquids

Question 149

All colligative properties stem from the _____ of the chemical potential of the liquid solvent as a result of the presence of the solute. a. Reduction b. Change c. Enlargement d. A or B or C, depending on the identities of the solute and solvent

Answer 149

a. Reduction

Question 150

In a process involving osmosis, at equilibrium, the chemical potential of the pure solvent side should be _____ the chemical potential of the side with solute. a. Less than b. More than c. Equal to d. Can’t be determined

Answer 150

c. Equal to

Question 151

When a solute is introduced to a liquid system, the entropy of the said system: a. Increases b. Decreases c. Stays the same d. Can’t be determined

Answer 151

a. Increases

Question 152

Among the following, which compound will produce the least lowering of the vapor pressure of a solution? a. sucrose, C12H22O11 b. Aluminum chloride, AlCl3 c. Table salt, NaCl d. Sodium sulfate, Na2SO4

Answer 152

a. sucrose, C12H22O11

Question 153

Which of the following statements is true? a. Trouton’s rule fails for highly polar liquids b. It is impossible to go from vapor phase to liquid phase without condensation c. For C compounds and P phases, there are a total of CP intensive variables to be specified d. At high pressures, the latent heat of vaporization is a measure of the strength of the intermolecular forces of the liquid

Answer 153

a. Trouton’s rule fails for highly polar liquids

Question 154

What is the significance of colligative property in physical chemistry? a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute b. It refers to the temperature, pressure and energy of fusion of volatile solutes in phase equilibrium c. It refers to the non-existence of pressure among molecules within the solute d. It refers to the temperature differentials exhibited by non-volatile solutes in reactions

Answer 154

a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute

Question 155

Are galvanic cells and electrolytic cells the same? Why? a. No. because galvanic cells are electrochemical cells in which chemical cells occur simultaneously; while in electrolytic cells, the chemical reaction is caused by an externally applied potential difference. b. No, because galvanic cells need a constant supply of electricity while electrolytic cells depend on intermittent source of power. c. Yes, because they are both electrochemical cells and their uses are common to each other d. Yes, because galvanic cells and electrolytic cells are both electrochemical cells.

Answer 155

a. No. because galvanic cells are electrochemical cells in which chemical cells occur simultaneously; while in electrolytic cells, the chemical reaction is caused by an externally applied potential difference.

Question 156

Determine the final volume of 0.51M KBr when the starter volume is 100mL. From a 50mL solution of 0.25M alanine, what volume will be required using 0.11M alanine? a. 196mL; 114mL b. 51mL; 33mL c. 179mL; 102mL d. 201mL; 120mL

Answer 156

a. 196mL; 114mL

Question 157

If one gallon of blood was added in three gallons of water, and one ounce of that dilution was added to 9 ounces of water, what is the final dilution when 7mL of that dilution was added to 563mL of water? a. 5.65x10-3 b. 2.24x10-2 c. 1.72x10-4 d. 3.11x10-4

Answer 157

d. 3.11x10-4

Question 158

In a titration experiment, 15.02mL of an HCl solution required 26.1mL of 0.32M sodium hydroxide. Determine the concentration of HCl. a. 2.15M b. 0.52M c. 1.12M d. 0.64M

Answer 158

b. 0.52M

Question 159

Determine the: 1. Moles of analyte 2. Volume of titrant to reach end point 3. pH at the start, halfway and at the endpoint for each of the titrations performed. For the titration shown as follows: 50mL of a weak base (pKb=5), 0.072M with 0.153M HCl. a. 3x10-3mol; 24mL; 10.84, 8.82, 5.06 b. 11.25x10-4mol; 12.22mL; 7.34, 2.11, 12.23 c. 10.35x10-1mol; 16mL; 5.32, 4.23, 8.45 d. 7.24x10-2mol; 11.25mL; 11.23, 5.31, 9.56

Answer 159

a. 3x10-3mol; 24mL; 10.84, 8.82, 5.06

Question 160

Determine the pH of a 0.21M solution of sodium benzoate in water at room temperature. (KA=6.3x10-5) a.6.35 b.4.37 c.0.74 d.2

Answer 160

c.0.74

Question 161

Determine the pH of a 0.05M solution of each salt: 1. Potassium acetate (KA=1.8x10-5) 2. Sodium benzoate 3. Potassium carbonate 4. Sodium dihydrogen phosphate 5. Ammonium nitrate a. 11.5, 8.45, 4.56, 4.26, 1.23 b. 10.65, 3.22, 11, 8.45, 5.27 c. 8.45, 4.26, 7, 11.5, 8.73 d. 8.73, 5.99, 8.45, 7.33, 7

Answer 161

d. 8.73, 5.99, 8.45, 7.33, 7

Question 162

When formic acid is 4.6% ionized in 0.105M of aqueous solution at room temperature, determine the ionization constant of the acid. If the solution containing 0.25N of 25mL acid is diluted to 202mL and titrated with 0.35 NaOH, calculate the pH value and the concentration of the hydrogen ion at the equivolume part. a. 2.2x10-4; 8.06; 8.7x10-9 b. 1.8x10-5; 9.1; 7.2x10-10 c. 4.1x10-4; 7.21; 6.4x10-10 d. 3.4x10-4; 6.32; 5.23x10-11

Answer 162

a. 2.2x10-4; 8.06; 8.7x10-9

Question 163

A solution of HCl and a monobaric acid is titrated with NaOH. If the initial volume of the solution is 100mL and the concentration of each moment is 0.011M and the ionization constant is 1.01x105 and the concentration of the titrant base is 0.1M, estimate the pH of the solution when 5mL and 15mL of the titrate has been added and the optimum pKa of a weak acid indicator to allow determination of the HCl present. a. 2.3, 5.0, 3.5 b. 3.7, 6.0, 4.5 c. 3.4, 4.5, 5.2 d. 4.2, 7.0, 6.2

Answer 163

a. 2.3, 5.0, 3.5

Question 164

If the normality of HCl is greater by 10% compared to KOH, estimate the normality of the HCl solution when 0.67g of (NH4)2SO4 is dissolved in water, treated with excess NaOH and the ammonia released is passed through a solution of 20mL of HCl. The excess acid solution is titrated using 15.01mL of KOH solution. a. 0.275N b. 3.17x10-3N c. 0.152N d. 2.32x10-2N

Answer 164

c. 0.152N

Question 165

Analyze and calculate the percentage of nickel in a 1.201g sample of nickel ore which was analyzed by the volumetric method. A solution of 48mL containing 1.4x10-2g of KCN/mL and the excess cyanide required half a milliliter of silver nitrate solution with 1.25x10-2g AgNO3 per milliliter. a. 9.36% b. 15.21% c. 12.5% d. 8.22%

Answer 165

c. 12.5%

Question 166

A certain volume of a solution of KMnO4 will oxidize sufficient potassium tetraoxalate that requires half of that volume using 0.201N of KOH solution for neutralization. Determine the quantity of KMnO4 in a liter of its solution. a. 4.213g b. 2.01g c. 8.621g d. 5.02g

Answer 166

b. 2.01g

Question 167

If aspirin is made using the raw materials salicylic acid and acetic anhydride with a yield of 75%, how many grams of aspirin will be produced A. 25 B. 15 C. 30 D. 1

Answer 167

A. 25

Question 168

Classify each of the following as homogeneous or heterogeneous: I. A door II. The air you breathe III. a cup of coffee (black) IV. The water you drink V. Salsa VI. Your lab partner A. hetero, homo, homo, homo, hetero, hetero B. hetero, hetero, homo, homo, homo, hetero C. homo, homo, homo, homo, hetero, homo D. homo, homo, hetero, hetero, homo, hetero

Answer 168

A. hetero, homo, homo, homo, hetero, hetero

Question 169

How many beta particles are emitted in the decomposition of 238U92 to 206Pb82? A. 4 B. 2 C. 6 D. 8

Answer 169

C. 6

Question 170

The decomposition of iodoethane in the gas phase proceeds according to the following reactions: C2H5I (g) → C2H4 (g) + HI (g) At 660 K, k = 7.2x10^-4 /s and at 720 K, k = 1.70x10^-2 /s. If the initial pressure of iodoethane is 894 torr at 245°C, what is the pressure of iodoethane after three half-lives? A. 429 torr B. 112 torr C. 356 torr D. 508 torr

Answer 170

B. 112 torr

Question 171

Where in the body does fatty acid synthesis occur? A. Mitochondrion B. Cytoplasm C. Ribosomes D. Golgi apparatus

Answer 171

B. Cytoplasm

Question 172

Suppose you have a phosphate buffer of pH 7.21. If you add more solid NaH2 PO 4 to this buffer, would you expect the pH of the buffer to increase, decrease, or remain unchanged? A. increase B. decrease C. remain the same D. either increase or decrease

Answer 172

B. decrease

Question 173

What structural characteristics do citric acid and malic acid have in common? A. They are heterocyclic compounds B. Both has three moieties of carboxylic acid C. They contain an alkene bridge D. They are both hydroxy acids

Answer 173

D. They are both hydroxy acids

Question 174

What is the difference between a coenzyme and a cofactor? A. Coenzyme activator is inorganic while cofactor is organic B. Coenzyme needs allosteric activator while cofactor requires conformational induction C. Cofactor contains heme groups, coenzyme has disulfide bridge D. Cofactor is more generic; it means a nonprotein part of an enzyme. A coenzyme is an organic factor.

Answer 174

D. Cofactor is more generic; it means a nonprotein part of an enzyme. A coenzyme is an organic factor.

Question 175

Who discovered phenolphthalein? A. Adolf von Baeyer B. Louis-Jacques Thenard C. Joseph Louis Gay-Lussac D. Albert Hofmann

Answer 175

A. Adolf von Baeyer

Question 176

How many high-energy phosphate bonds are in the ATP molecule? A. 1 B. 2 C. 3 D. 0

Answer 176

B. 2

Question 177

Classify each of the following as an element, a compound, or a mixture. a) diamond b) sea water c) gasoline d) wine e) a pebble f) bronze A. element, mixture, mixture, mixture, mixture, mixture B. compound, mixture, compound, mixture, mixture, element C. element, compound, compound, element, compound, compound D. compound, compound, mixture, compound, compound, mixture

Answer 177

A. element, mixture, mixture, mixture, mixture, mixture

Question 178

Applying the Octet Rule, determine how many electrons each must each atom gain or loss to acquire an electron configuration identical to the noble gas nearest to it in atomic number; Sr, S and Si. A. krypton; argon, argon and krypton B. neon; argon and krypton; krypton C. none of these D. argon; krypton, krypton and argon

Answer 178

A. krypton; argon, argon and krypton

Question 179

A large stream has a reoxygenation constant of 0.4 day −1and a velocity of 0.85 m/s. At the point at which an organic pollutant is discharged, it is saturated with oxygen at 10 mg/L (DO = 0). Below the outfall the ultimate demand for oxygen is found to be 20 mg/L, and the deoxygenation constant is 0.2 day−1 . What is the dissolved oxygen 48.3 km downstream? A. 7.8 mg/L B. 5.0 mg/L C. 2.2 mg/L D. 6.5 mg/L

Answer 179

A. 7.8 mg/L

Question 180

Glucose is the only carbohydrate compound that the brain can use for energy. Which pathway is mobilized to supply the need of the brain during starvation? A. gluconeogenesis B. glycolysis C. glycogenesis D. none of these

Answer 180

A. gluconeogenesis

Question 181

Predict whether each of the following nuclides is stable or unstable (radioactive). If the nuclide is unstable, predict the type of radioactivity you would expect it to exhibit. 45-K, 56-Fe, 11-Na, 194-Tl. A. unstable-alpha production, unstable-positron production, stable, unstable-electron capture B. unstable-beta production, stable, unstable-positron production, unstable-alpha production C. stable, stable, stable, stable D. stable, unstable-alpha production, unstable-electron capture, unstable-alpha production

Answer 181

B. unstable-beta production, stable, unstable-positron production, unstable-alpha production

Question 182

Crystals of a material are suspended in the middle of a cup of water at 2 deg C. How might you enable the crystals to rise to the surface of the water so that you can harvest them? a. Add more crystals b. Add more water c. Decrease the temperature of water to 0 deg C d. Increase the temperature of water to 4 deg C

Answer 182

d. Increase the temperature of water to 4 deg C

Question 183

What is the organic formula of lindane, chlorinated pesticide which has been banned? It is composed of 24.781% carbon, 2.082% hydrogen, 73.142% chlorine and has a molecular mass of 290.834. A. C3H6Cl6 B. C3H6Cl12 C. C6H12Cl6 D. (CHCl)6

Answer 183

D. (CHCl)6

Question 184

Predict the order of the melting points of triglycerides containing fatty acids, as follows: I. Palmitic, palmitic, stearic II. Oleic, stearic, palmitic III. Oleic, linoleic, oleic A. III < II < I B. II < I < III C. I < III < II D. II < III < I

Answer 184

A. III < II < I

Question 185

A reported synthesis of the transuranium element bohrium (Bh) involved the bombardment of berkelium-249 with neon-22 to produce bohrium-267. The half-life of bohrium-267 is 15.0 seconds. If 199 atoms of bohrium-267 could be synthesized, how much time would elapse before only 11 atoms of bohrium267 remain? A. 50 s B. 79 s C. 63 s D. 44 s

Answer 185

C. 63 s

Question 186

How many molecules are in one drop of water? A. 1.0x10^21 B. 1.0x10^24 C. 1.7x10^24 D. 1.7x10^21

Answer 186

D. 1.7x10^21

Question 187

Which of the following objects are chiral (assume that there is no label or other identifying mark)? a) Pair of scissors b) Tennis ball c) Paper clip d) Beaker e) The swirl created in water as it drains out of a sink or bathtub A. chiral, chiral, chiral, chiral, chiral B. achiral, chiral, chiral, achiral, chiral C. chiral, achiral, chiral, chiral, achiral D. chiral, achiral, achiral, achiral, chiral

Answer 187

D. chiral, achiral, achiral, achiral, chiral

Question 188

Consider the reaction 2O(g) à O 2(g). Predict the signs of deltaH and deltaS. Would the reaction more spontaneous at high or low temperatures? A. deltaH = -, deltaS = +, high B. deltaH = +, deltaS = +, high C. deltaH = -, delta S = -, low D. deltaH = +, deltaS = -, low

Answer 188

C. deltaH = -, delta S = -, low

Question 189

A sample of municipal sewage is diluted to 1% by volume prior to running a BOD 5 analysis. After 5 days the oxygen consumption is determined to be 2.00 mg · L−1 . What is the BOD 5 of the sewage? A. 150 mg/L B. 300 mg/L C. 250 mg/L D. 200 mg/L

Answer 189

D. 200 mg/L

Question 190

In each case, tell whether the bond is ionic, polar covalent, or nonpolar covalent: Br2, BrCl, HCl, SrF2, SiH4, CO, N2 , CsCl A. nonpolar covalent, nonpolar covalent, polar covalent, ionic, nonpolar covalent, polar covalent, nonpolar covalent, ionic B. polar covalent, ionic, polar covalent, nonpolar covalent, nonpolar covalent, nonpolar covalent, polar covalent, polar covalent C. nonpolar covalent, nonpolar covalent, ionic, nonpolar covalent, polar covalent, nonpolar covalent, ionic D. nonpolar covalent, polar covalent, nonpolar covalent, nonpolar covalent, polar covalent, polar covalent, ionic, polar covalent

Answer 190

A. nonpolar covalent, nonpolar covalent, polar covalent, ionic, nonpolar covalent, polar covalent, nonpolar covalent, ionic When ΔE > 0.4 - it is polar

Question 191

How to differentiate alkane alkene and alkyne? A. combustion on an empty beaker B. nature of carbon and its branching C. reaction with Br2 D. all of these

Answer 191

C. reaction with Br2

Question 192

How many carbon atoms in olvanil? A. 40 B. 38 C. 15 D. 26

Answer 192

D. 26

Question 193

These compounds are formed by the reaction of acids with alcohol. A. Ethers B. Esters C. Bases D. Enzymes

Answer 193

B. Esters

Question 194

The Tanay Rizal Stone Works employs six workers who produce uncompacted waste from the products formed for building decors. If the density of the uncompacted waste is 40 kilograms per cubic meters, determine the annual volume of solid waste produced by the factory assuming a waste generation volume rate of one kilogram per capita per day. A. 3.22 cubic meters B. 5.56 cubic meters C. 8.01 cubic meters D. 4.65 cubic meters

Answer 194

D. 4.65 cubic meters

Question 195

Choose the process that occurs with a decrease in entropy A. freezing of water B. boiling of water C. dissolving salt in water D. sublimation of dry ice

Answer 195

A. freezing of water

Question 196

Why is it accurate to assume that the carbon-14 to carbon-12 ratio in a living plant remains constant over the lifetime of the plant? I. Carbon 14 is continually generated in the upper atmosphere by the production and decay of nitrogen 14. II. Carbon 14 incorporated into carbon dioxide and the other compounds are distributed worldwide as part of the carbon cycle. III. The continual formation of carbon-14; transfer of isotope within the oceans, atmospheres and biosphere; and the decay of living matter keep the supply constant. A. T, F, T B. F, F, F C. T, T, T D. F, F, T

Answer 196

C. T, T, T

Question 197

Consider the Earth to be a blackbody with average temperature 15degC and surface area equal to 5.1x10^14 m^2. Find the rate at which energy is radiated by the Earth and the wavelength at which maximum power is radiated. Compare this peak wavelength with that for a 5800-K blackbody (the sun. A. 1x10^19 W, 12.9x10^6 m (earth, 0.33x10^6 m (sun) B. 2x10^17 W, 10.1x10^6 m (earth, 0.48x10^6 m (sun) C. 4x10^16 W, 15.5x10^6 m (earth, 0.57x10^6 m (sun) D. 3x10^15 W, 13.6x10^6 m (earth, 0.20x10^6 m (sun)

Answer 197

B. 2x10^17 W, 10.1x10^6 m (earth, 0.48x10^6 m (sun)

Question 198

The density of acetylene gas, in a 4-L container at 0 degC and 2 atm pressure is 0.02 g/mL. What would be the density of the gas under identical temperature and pressure if the container were partitioned into two 2-L compartments? A. 0.03 g/mL B. 0.04 g/mL C. 0.01 g/mL D. 0.02 g/mL

Answer 198

D. 0.02 g/mL

Question 199

Determine which of the following will float or sink in water: balsa wood, ethylene, glycol, table salt, ethanol A. float, float, float. float B. float, sink, sink. float C. sink, float, sink. float D. sink, sink, sink. sink

Answer 199

B. float, sink, sink. float

Question 200

Chlorine gas was first prepared in 1774 by C. W. Scheele by oxidizing sodium chloride with manganese(IV) oxide. The reaction is NaCl(aq) + H2SO4(aq) + MnO2(s) --> Na2SO4(aq) + MnCl2(aq) + H2O(l) + Cl2(g) A. 4, 2, 1, 2, 1, 1, 2 B. 3, 3, 2, 1, 1, 2, 3 C. 1, 4, 2, 3, 2, 2, 1 D. 2, 3, 4, 1, 1, 2, 2

Answer 200

A. 4, 2, 1, 2, 1, 1, 2

Question 201

Boron-10, an effective absorber of neutrons, is used in control rods of uranium-235 fission reactors to absorb neutrons and thereby control the rate of reaction. Boron-10 absorbs a neutron and then emits an a particle. Write a balanced equation for this nuclear reaction and identify the nucleus formed as an intermediate between boron-10 and the final nuclear product. A. Li B. Be C. Ca D. Na

Answer 201

A. Li

Question 202

The mass of a proton is 1.67 3 10224 g. The mass of a grain of salt is 1.0 3 1022 g. How many protons would it take to have the same mass as a grain of salt? A. 7x10^22 protons B. 1x10^21 protons C. 5x10^21 protons D. 6x10^21 protons

Answer 202

D. 6x10^21 protons

Question 203

Using the data given below: Calculate the DO concentration just mixing Oz WWTP Effluent Babbling Run Flow, m^3/s 0.36 4.8 Ultimate BOD at 20degC, mg/L 27 35 DO, mg/L 0.9 8.5 A. 6 mg/L B. 5 mg/L C. 8 mg/L D. 7 mg/L

Answer 203

C. 8 mg/L

Question 204

Answer the following questions Is H + (aq) capable of oxidizing Cu(s) to Cu2+(aq)? Is Fe 3+ (aq) capable of oxidizing I-(aq)?? Is H2 (g) capable of oxidizing Ag+(aq)? A. yes, yes, yes B. yes, no, no C. no, yes, yes D. no, no, no

Answer 204

C. no, yes, yes

Question 205

Determine whether TRUE or FALSE about the constitutional isomer. A.) They have the same molecular formula B.) They have the same molecular weight C.) They have the same connectivity to their atoms D.) They have the same physical properties A. T; F; F; F B. T; T; F; F C. F; T; T; T D. F; F; T; T

Answer 205

B. T; T; F; F

Question 206

Suppose you obtain a sample of barium 122 weighing 10.0 g and it takes 10 minutes to set up an experiment. How many grams of Barium – 122 will remain at the point when you begin the experiment? A. 1.5 g B. 0.31 g C. 2.1 g D. 4.0 g

Answer 206

C. 2.1 g 122-Ba half-life: 2 min

Question 207

Number of double bonds in geraniol A. 3 B. 1 C. 0 D. 2

Answer 207

D. 2

Question 208

A 1.60-g sample of a mixture of naphthalene and anthracene is dissolved in 20.0 g benzene. The freezing point of the solution is 2.810 C. What is the composition as mass percent of the sample mixture? A. 44% naphthalene B. 60% naphthalene C. 36% naphthalene D. 57% naphthalene

Answer 208

A. 44% naphthalene

Question 209

Determine whether the following statements are TRUE or FALSE. a) For all adiabatic processes, the entropy change of the system must be zero b) For one component system, it is possible for two phases in equilibrium to have different chemical potentials. c) The change in Gibb’s free energy can be negative for a cyclic process. d) A condition for equilibrium is that(∆A) T, F =0 A. T, T, T, T B. F, T, F, T C. T, F, T, F D. F, F, F, F

Answer 209

D. F, F, F, F

Question 210

Are the following processes exothermic or endothermic? a) When solid KBr is dissolved in water, the solution gets colder. b) Natural gas (CH4) is burned in a furnace. c) When concentrated H2SO4 is added to water, the solution gets very hot. d) Water is boiled in a teakettle. A. exothermic, exothermic, endothermic, endothermic B. endothermic, exothermic, endothermic, endothermic C. exothermic, exothermic, exothermic, endothermic D. endothermic, exothermic, exothermic, endothermic

Answer 210

D. endothermic, exothermic, exothermic, endothermic

Question 211

Determine the molecular weights of glucose and urea respectively. A. 180 amu; 60 amu B. 84 amu; 38 amu C. 120 amu; 72 amu D. 96 amu; 36 amu

Answer 211

A. 180 amu; 60 amu

Question 212

Balancing C2H5SH + O2 → CO2+ H2O + SO A. 1, 8, 4, 5, 1 B. 2, 9, 4, 6, 2 C. 2, 7, 4, 4, 2 D. 1, 5, 4,3, 1

Answer 212

C. 2, 7, 4, 4, 2 Typo since it should be SO2

Question 213

Notation on alkane containing Cl A. chloro B. chloride C. chlorate D. chloric

Answer 213

A. chloro

Question 214

What will happen to ice at 0°C if the pressure decreases from 1 atm to 0.001 atm? A. it becomes vapor B. it remains solid C. it becomes liquid D. both a and c are possible

Answer 214

A. it becomes vapor

Question 215

The heat of combustion of methane, the major component of natural gas, is 213 kcal/mol. The heat of combustion of propane, the major component of LPG or bottled gas, is 530 kcal/mol. On a kcal/mol basis, which of these two fuels is the better source of heat energy? On a kcal/g basis, which of these two fuels is the better source of heat energy? A. propane, propane B. methane, propane C. propane, methane D. methane, methane

Answer 215

C. propane, methane

Question 216

In year 2, the farmer plans to plant soybeans. No manure is to be applied during this crop year. The soybean is a legume and can fix adequate atmospheric nitrogen to produce the desired yield of soybeans. Additional nitrogen fertilizer does not produce significant yield increases. Soybeans require 50 kg N –(hectare)^- 1 , 35 kg P -(hectare) ^−1 , and 225 kg K - (hectare) ^−1 according to the local extension agent. Estimate the remaining phosphorus after the corn is harvested. The corn crop from year 1 would have removed 52 kg of P2O 5 – hectare^-1 and 38 kg of K2O - hectare^−1. A. 48.5 kg / hectare B. 77.3 kg / hectare C. 36.9 kg / hectare D. 50.7 kg / hectare

Answer 216

B. 77.3 kg / hectare

Question 217

A deer eats 25 kg of herbaceous material per day. The herbaceous matter is approximately 20% dry matter (DM) and has an energy content of 10 MJ · (kg DM)−1 . Of the total energy ingested per day, 25% is excreted as undigested material. Of the 75% that is digested, 80% is lost to metabolic waste products and heat. The remaining 20% is converted to body tissue. Calculate the percentage of energy consumed that is converted to body tissue. A. 15% B. 20% C. 19% D. 24%

Answer 217

A. 15% 75%*20% = 15%

Question 218

It is known as Water Quality Guidelines and General Effluent Standards of 2016. a. DAO 34 b. DAO 35 c. RA 9275 d. DAO No. 2016-08

Answer 218

d. DAO No. 2016-08

Question 219

Class of water intended for primary contact recreation such as bathing, swimming, skin diving, etc. a. Class AA b. Class A c. Class B d. Class C

Answer 219

c. Class B

Question 220

Gas responsible for the rotten egg odor of wastewater. a. ammonia b. amines c. mercaptans d. hydrogen sulfide

Answer 220

d. hydrogen sulfide

Question 221

The resistance of water to the passage of light through it is a measure of the a. color b. turbidity c. hardness d. dissolved gases

Answer 221

b. turbidity

Question 222

Which of the following apparatus is not used in measuring turbidity? a. Jackson Turbidimeter b. Secchi Disk Depth c. Photoelectric Colorimeter d. none of these

Answer 222

c. Photoelectric Colorimeter

Question 223

The total solids in water are due to the presence of a. suspended and dissolved solids b. suspended and floating solids c. colloidal and settleable solids d. colloidal and bacterial load

Answer 223

a. suspended and dissolved solids

Question 224

Sodium ions contribute to which characteristics of water a. pH b. color c. hardness d. total dissolved solids

Answer 224

d. total dissolved solids

Question 225

The following test results were obtained for a wastewater sample taken from a treatment plant. All of the tests were performed using a sample size of 50 ml. Determine the concentration of the total volatile solids in waste water. Tare mass of evaporating dish 62.003 g Mass of evaporating dish plus residue after evaporation at 1050C 62.039 g Mass of evaporating dish plus residue after ignition at 5500C 62.036 g Tare mass of Whatman filter paper 1.540 g Residue on Whatman filter paper after drying at 1050C 1.552 g Residue on Whatman filter paper after ignition at 5500C 1.549 g a. 60 mg/L b. 240 mg/L c. 480 mg/L d. 720 mg/L

Answer 225

a. 60 mg/L

Question 226

Dissolved oxygen in water is reduced during a. winter b. summer c. spring d. autumn

Answer 226

b. summer

Question 227

The color of wastewater containing little or no dissolved oxygen is a. gray b. black c. brown d. reddish brown

Answer 227

b. black

Question 228

In the determination of BOD, the reaction takes place at a. 20°C b. 30°C c. 40°C d. 50°C

Answer 228

a. 20°C

Question 229

In determination of BOD, the reaction takes place in the dark because a. The microorganisms are sensitive to light. b. Oxygen is sensitive to light. c. The reaction is enhanced in the dark. d. Algae may be present and produce oxygen.

Answer 229

d. Algae may be present and produce oxygen.

Question 230

A newly graduate chemical engineer was assigned to team of engineers in food processing plant. The problem given was to determine the best locations for new two plants, considering two possible areas where rivers were available. The following data were given: Effluent Plant A Plant B Flow, m3/s 0.05 0.05 Ultimate BOD, kg/d 129.6 129.6 Dissolved oxygen, mg/L 0.9 0.9 Temperature, degC 25 25 Reaeration coefficient 0.11 0.9 River Flow, m3/s 0.5 0.5 Ultimate BOD, kg/d 19 19 Dissolved oxygen, mg/L 5.8 5.8 Temperature, degC 25 25 Speed (m/s) 0.1 0.2 Average depth (m) 4 4 BED activity coefficient 0.2 0.2 Which plant will be located near what river? a. B – A b. B – B c. A – B d. A – A

Answer 230

b. B – B

Question 231

Determine the BEST combination of plant and location to BEST conserve the environment, given the following data: kd = deoxygenation rate constant kr = reaeration rate constant Tc = travel time of wastewater discharge D = oxygen deficit DO = dissolved oxygen actual concentration Factor Sugar Plant (A) Pasig River (PR) Marikina River (MR) kd 0.15. 0.15 kr 0.17 0.25 Tc 5.18 4.10 D 7.98 6.62 DO 0.40 1.76 Factor Methanol Plant (B) Pasig River (PR) Marikina River (MR) kd 0.11 0.10 kr 0.17 0.25 Tc 5.86 4.47 D 6.51 5.32 DO 1.87 3.06 a. Plant (B) in Marikina River b. Plant (B) in Pasig River c. Plant (A) in Marikina River d. Plant (A) in Pasig River

Answer 231

a. Plant (B) in Marikina River

Question 232

Which of the following is not a physical characteristic of wastewater? a. odor b. turbidity c. color d. hardness

Answer 232

d. hardness

Question 233

It is the phenomenon that results in the overabundance of algae growth in bodies of water. It is also the natural process of nutrient enrichment that occurs over time in a body of water. a. biomagnification b. eutrophication c. anaerobic respiration d. thermal inversion

Answer 233

b. eutrophication

Question 234

Measure of the total organic and ammonia nitrogen in the wastewater. It also gives a measure of the availability of nitrogen for building cells. a. TKN b. COD c. NBOD d. none of these

Answer 234

a. TKN

Question 235

Involves the accumulation of trace metals through each species of the food chain. a. biomagnification b. denitrification c. anaerobic respiration d. eutrophication

Answer 235

a. biomagnification

Question 236

A trace metal which causes Itai-itai diseases is a. cadmium b. silver c. mercury d. chromium

Answer 236

a. cadmium

Question 237

A trace metal which causes Minamata diseases is a. cadmium b. silver c. mercury d. chromium

Answer 237

c. mercury

Question 238

Hardness of water is usually expressed in parts per million of a. MgSO4 b. CaCO3 c. Na2CO3 d. CaCl2

Answer 238

b. CaCO3

Question 239

A sample of groundwater has an 150 milligrams per liter of Ca2+ and 60 milligrams per liter of Mg2+, how would this water be classified a. soft b. moderately hard c. slightly hard d. very Hard

Answer 239

d. very Hard

Question 240

The following mineral analysis was reported for a water sample taken from well No. 1 at Magnolia, Illinois (Woller and Sanderson, 1976b). Determine the noncarbonate hardness (in mg/Las CaCO3), using the predominant polyvalent cation definition of hardness. Well No. 1, Lab No. B109535, April 23, 1973 (Note: All reported as mg/L as the ion unless stated otherwise.) Mineral Concentration Mineral Concentration Iron (2+) 0.42 Silica 20.0 Manganese 0 .04 Fluoride 0.3 Ammonium 11.0 Boron 0.3 Sodium 78.0 Nitrate 0.0 Potassium 2.6 Chloride 9.0 Calcium 78.0 Sulfate 29.0 Magnesium 40.0 Zinc 0.01 Barium 0.5 Alkalinity 494.035 as CaCO3 Copper 0.01 pH 7.7 units a. 0 b. 494 c. 327 d. 110

Answer 240

a. 0

Question 241

Type of wastewater treatment that employs physical and chemical treatment methods to remove or reduce a high percentage of suspended solids and toxic materials. a. Primary Treatment b. Secondary Treatment c. Tertiary Treatment d. Minor Treatment

Answer 241

a. Primary Treatment

Question 242

Hard water can be softened by a. letting the calcium or magnesium ions settle out b. passing it through an ion exchanger c. chlorination d. filtration

Answer 242

b. passing it through an ion exchanger

Question 243

Removal of all settleable particles rendered settleable under the influence of gravity, basically the theory of gravity under the influence of which all particles heavier than water tend to settle down. a. screening b. flotation c. sedimentation d. flocculation

Answer 243

c. sedimentation

Question 244

In facultative stabilization pond, the sewage is treated by a. aerobical bacteria b. anaerobic bacteria c. algae d. both (a) and (b)

Answer 244

d. both (a) and (b)

Question 245

Process whereby coarse matter (suspended or floating) of a certain size can be strained out of flowing water with the aid of bars, fines wires or rocks. a. screening b. sedimentation c. flotation d. flocculation

Answer 245

a. screening

Question 246

Water treatment that destroys disease-causing bacteria, nuisance bacteria, parasites and other organisms and removes soluble irons, manganese and hydrogen sulfide from water. a. disinfection b. flocculation c. chlorination d. coagulation

Answer 246

c. chlorination

Question 247

A code for plastics used for food wrapping, trash bags, grocery bags and baby diapers. a. 2 b. 3 c. 4 d. 5

Answer 247

a. 2

Question 248

It is the international salute that is currently the primary basis of the Philippines in its latest environmental dispute with Canada. a. Kyoto Protocol b. Basel Convention c. Copenhagen Talks d. Montreal Protocol

Answer 248

b. Basel Convention

Question 249

Determine the area required for a new landfill site with a projected life of 30 years for a population of 250,000 generating 2.02 kg per capita per day. The density of the compacted waste is 470 kg/m3. The height of the landfill cannot exceed 15 m. a. 56.6 ha b. 78.4 ha c. 49.2 ha d. 68.3 ha

Answer 249

b. 78.4 ha

Question 250

Ecological Solid Waste Act of 2000 is otherwise known as a. RA 6969 b. RA 8749 c. RA 9003 d. RA 9275

Answer 250

c. RA 9003

Question 251

“Smokey Mountain” is a typical example of a facility for solid waste. It is classified as a. open dumping site b. sanitary landfill c. transfer station d. material recovery facility

Answer 251

a. open dumping site

Question 252

A global treaty that aims to diminish and eventually phase out chlorofluorocarbons. a. Stockholm Convention b. Kyoto Protocol c. Montreal Protocol d. none of these

Answer 252

c. Montreal Protocol

Question 253

Collective term for the initial POPs identified by the Stockholm Convention a. Dirty 12 b. 12 POPs c. Dirty Dozens d. EDCs

Answer 253

c. Dirty Dozens

Question 254

It is an odorless and colorless gas that is lethal to humans with exposure as short as a few minutes to concentrations exceeding 5000 ppm. It reacts with hemoglobin in the blood rendering the latter incapable of carrying oxygen to the body. a. carbon monoxide b. hydrogen supplied c. sulfur dioxide d. sulfur trioxide

Answer 254

a. carbon monoxide

Question 255

Pick out the wrong statement. a. The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone. b. Mesosphere is characterized by very low atmosphere pressure and low temperature. c. Troposphere is a dusty zone containing water vapor and clouds. d. The radio waves used in the long-distance radio communication are reflected to earth by stratosphere.

Answer 255

d. The radio waves used in the long-distance radio communication are reflected to earth by stratosphere.

Question 256

The rate at which temperature in the atmosphere changes with altitude is called a. temperature change b. thermal rate c. lapse rate d. vertical rate

Answer 256

c. lapse rate

Question 257

Which biogeochemical cycle has bacteria living in a symbiotic relationship with the roots of legumes? a. oxygen b. carbon c. nitrogen d. phosphorous

Answer 257

c. nitrogen

Question 258

By which process is carbon dioxide released from plants back into the atmosphere? a. evaporation b. respiration c. photosynthesis d. phosphorylation

Answer 258

b. respiration

Question 259

Process where decomposers return back the nitrogen to the soils through the remains and waste of plants and animals a. ammonification b. nitrogen fixation c. denitrification d. ammonolysis

Answer 259

a. ammonification

Question 260

Which of the acid combination is the dominant composition of acid rain? a. nitric acid and carbonic acid b. nitric acid and sulfuric acid c. carbonic acid and sulfuric acid d. none of the above

Answer 260

b. nitric acid and sulfuric acid

Question 261

By which process is carbon dioxide released from plants back into the atmosphere? a. evaporation b. respiration c. photosynthesis d. phosphorylation

Answer 261

b. respiration

Question 262

Mr. and Mrs. Konzzumer have no children. In an average week they purchase and bring into their house approximately 50 kg of consumer goods (food, magazines, newspapers, appliances, furniture, and associated packaging). Of this amount, 50% is consumed as food. Half of the food is used for biological maintenance and ultimately released as CO2 ; the remainder is discharged to the sewer system. The Konzzumers recycle approximately 25% of the solid waste that is generated. Approximately 1 kg accumulates in the house. Estimate the amount of solid waste they place at the curb each week. A. 22 kg B. 18 kg C. 25 kg D. 12 kg

Answer 262

B. 18 kg

Question 263

An environmental engineering student was very interested in the reaction of the chemical 2,4,6-chickenwire. She went into the lab and found that 2,4,6-chickenwire degrades in water. During her experiments she collected the data in the following table. Determine if the reaction is zero-, first-, second-, third-order with respect to the concentration of 2,4,6-chickenwire. A. zero B. first C. second D. third

Answer 263

B. first

Question 264

Given the following temperature and elevation data, determine the stability of the atmosphere. Elevation, m [2,324] Temperature, 0 C [14.35,11.13] A. stable B. neutral C. inversion D. unstable

Answer 264

B. neutral

Question 265

A power plant in a college town is burning coal on a cold, clear winter morning at 8:00 A.M. with a wind speed of 2.6 m·s −1 measured at 30 m elevation and an inversion layer with its base at a height of 697 m. The effective stack height is 30 m. Calculate the distance downwind X L at which the plume released will reach the inversion layer and begin to mix downward. A. 7.9 km B. 4.3 km C. 5.8 km D. 6.1 km

Answer 265

C. 5.8 km

Question 266

Define the relationship between the number of electrons in the valence shell and the number of covalent bonds it forms; a) carbon, b) nitrogen, c) oxygen, and d) hydrogen: A. C = 4 electrons; 4 bonds N = 5 electrons; 3 bonds O = 6 electrons; 2 bonds H = 2 electrons; 2 bonds B. C = 5 electrons 2 bonds N = 6 electrons: 4 bonds O = 3 electrons; 1 bond H = 2 electrons; 3 bonds C. C = 6 electrons; 13 bonds N = 4 electrons; 2 bonds O = 2 electrons; 1 bond H = 2 electrons; 1 bond D. C = 2 electrons; 4 bonds N= 3 electrons; 3 bonds O = 2 electrons; 2 bonds H = 4 electrons; 3 bonds

Answer 266

A. C = 4 electrons; 4 bonds N = 5 electrons; 3 bonds O = 6 electrons; 2 bonds H = 2 electrons; 2 bonds

Question 267

A magician rotates a pail of water in a vertical circle with a radius of 0.50 meter amazes the audience because no water spilled out. What is the minimum speed at which no water will spill out? A. 3.13 m/sec/2 B. 1.23 m/sec/2 C. 7.2 m/sec2 D. 6.4 m/sec2

Answer 267

A. 3.13 m/sec/2

Question 268

A chemical engineering professor recorded her household waste generation as shown below. If a container volume is 0.076 cubic meter, what is the average density of the solid waste produced the household. Each empty container has a mass of 3.61 kilograms. [Date, Can Number, Gross mass] A. 58.50 kg/cu. m B. 66.32 kg/cu. m C. 75.21 kg/cu. m D. 49.87 kg/cu. m

Answer 268

A. 58.50 kg/cu. m

Question 269

We heat 50.0 g of an unknown substance by adding 205 cal, and its temperature rises by 7.0°C. Identify the substance. A. water B. ethanol C. benzene D. acetic acid

Answer 269

B. ethanol

Question 270

In electrochemistry, specific conductance is defined as (1000/N)x K, where N is the normality of the salt solution and K is the specific conductance, current is carried by oth anions and cation to a different degree. Thus the equivalence of a salt is the sum of the ionic conductances of the cation and anion. If the ionic conductance of Na + is 50.1 and that chloride is 76.3 what is the estimated concentration of NaCl in mg/L? The specific conductance of NaCl is 125 x 106 . A. 49 B. 58 C. 29 D. 38

Answer 270

B. 58

Question 271

Do isotopes of the heavy elements (for example, those from atomic number 37 to 53) contain more, the same, or fewer neutrons than protons? A. more B. same C. fewer D. none of these

Answer 271

A. more

Question 272

The purpose of control rods in a fission reactor is to: A. cool down the reactor fuel. B. prevent oxygen from reaching the fuel. C. absorb neutrons generated in the fission process. D. absorb electrons emitted in the fission process.

Answer 272

C. absorb neutrons generated in the fission process.

Question 273

An aqueous solution of an unknown salt of ruthenium is electrolyzed by a current of 2.50 A passing for 50.0 min. If 2.618 g Ru is produced at the cathode, what is the charge on the ruthenium ions in solution? A. +3 B. +4 C. +5 D. +6

Answer 273

A. +3

Question 274

A landfill that is 12 ha in area has a liner of thickness 0.9 m. Each year 1700 m 3 of leachate is collected. The hydraulic conductivity of the liner is 3.9×10^−10 m · s^−1 . What is the head of water above the liner? A. 2.33 m B. 0.85 m C. 1.04 m D. 3.96 m

Answer 274

C. 1.04 m

Question 275

Balance the following chemical equation: _Al + _NH 4 ClO 4 → _Al 2 O 3 + _AlCl 3 + _NO + _H 2 O A. 3, 1, 3, 1, 3, 6 B. 3, 3, 1, 3, 1, 6 C. 3, 3, 1, 1, 3, 6 D. 3, 1, 1, 1, 3, 6

Answer 275

C. 3, 3, 1, 1, 3, 6

Question 276

Balancing C2H5SH + O2 → CO2 + H2O + SO A. 1, 8, 4, 5, 1 B. 2, 9, 4, 6, 2 C. 2, 7, 4, 4, 2 D. 1, 5, 4, 3, 1

Answer 276

B. 2, 9, 4, 6, 2

Question 277

Balance the equation _(NH2) 2CO + _H2O = _CO2 + _NH4 + _OH A. 1, 1, 2, 1 B. 1, 1, 1, 1 C. 2, 1, 1, 1 D. 3, 2, 2, 1

Answer 277

A. 1, 1, 2, 1

Question 278

Balance the equation when ethanol is used as formula one fuel for racing cars, assuming the complete combustion of air. A. 1,2,4,3 B. 4,3,1,2 C. 2,3,2,4 D. 3,1,3,1

Answer 278

C. 2,3,2,4 Should not be ethanol but methanol

Question 279

A voltaic cell is represented by the following equation: Fe(s) + Zn2+ (aq) → Fe2+ (aq) + Zn (s) Which electrode is the anode and which electrode is the cathode?

Answer 279

Anode = Fe and Cathode = Zn LEORA, GEROA

Question 280

Mean distance from the equator to the north pole is:

Answer 280

1X10^7 m

Question 281

If a person breathes 100 breathes per minute and is aged 75, how many breathes will he/she have during his lifespan? A. 3.942 x 10^9 B. 5.256 x 10^6 C. 4.923 x 10-6 D. 6.044 x 10-5

Answer 281

A. 3.942 x 10^9 If this is not in the choices pick 5.256 x 10^6 since there's a typo that they didnt use 75 yrs

Question 282

Determine the volume in mL of 1mol of pure ethyl alcohol.

Answer 282

58mL

Question 283

If high octane gasoline with density 0.71 is used by a BMW on NLEX to travel to Tarlac 125 mi away and a gas mileage of 19.75 mi/gal estimate the quantity in kg of carbon dioxide produced.

Answer 283

52kg

Question 284

Iodine vapor forms iodine crystals when it touches a cold surface. What is the reverse of the process being described?

Answer 284

sublimation

Question 285

What is the formula of the ionic compound that is forced between the following ions: lithium and chloride ions; lithium and oxide ions; lithium and nitride ions? A. Li3Cl, Li3O2, LiN B. Li4Cl2, Li3O3; LiN3N3 C. Li2Cl2, LiO2, LN3 D. LiCl, Li2O, Li3N

Answer 285

D. LiCl, Li2O, Li3N

Question 286

What is the chemical formula of aspirin? A. C8H9O3 B. C9H8O4 C. C8H13O5 D. C10H34O

Answer 286

B. C9H8O4

Question 287

Which of the following formula is red lead? A. PbO B. Pb4O6 C. Pb2O4 D. Pb3O4

Answer 287

D. Pb3O4

Question 288

What is the empirical formula of a sample of cement found to contain 14.21 grams of molybdenum and 8.31 grams of silicon?

Answer 288

MoSi2

Question 289

What is the common name of this compound C6H5OCH3 ? A. Aniline B. Styrene C. Cumene D. Anisole

Answer 289

D. Anisole

Question 290

What is the formula of melamine? A. C3H6N6 B. C3H8N6 C. C4H7N8 D. C4H8N6

Answer 290

A. C3H6N6

Question 291

From which plant is capsaicin extracted?

Answer 291

Capsicum

Question 292

Give the technical names of Sc3+ , Ti 2+ and Sr2+ A. Transition metal ions B. Scandium 3 plus ion; Titanium 2 plus ion; Strontium 2 plus C. Scandium (III) ion; Titanium (II) ion; Strontium (II) ion D. Scandium 44/31 ion; Titanium 47/22 ion; Strontium 97/38 ion

Answer 292

C. Scandium (III) ion; Titanium (II) ion; Strontium (II) ion

Question 293

Determine the gram molecular weights and equivalent weights of the following: MgCO3; CO2; K2HPO4 and NaNO3. Make the appropriate assumptions A. 47.8/51.2; 66.4/71.1; 48.5/35; 67.5/46 B. 52.2/65; 134/36; 88/125; 120/55 C. 84.4/42.3; 44.2/22.3; 175/88; 85.2/85.3 D. 86.2/46; 48.1/51.1; 120/101; 96.3/102

Answer 293

C. 84.4/42.3; 44.2/22.3; 175/88; 85.2/85.3

Question 294

What is the molecular weight in amu/g/mol of 11-tetradecenyl acetate? (amu C16H30O2) A. 382.4 B. 25.4 C. 196.2 D. 505.8

Answer 294

B. 25.4

Question 295

What is the chemical formula of Alar?

Answer 295

C6H12N2O3

Question 296

Calculate the number of moles of hydrogen ion that is required to form 1.24 moles of hydrogen? What is the mass in grams of zinc to form 0.621 mole of hydrogen? A. None of these B. 2.44 moles hydrogen; 40.6 grams zinc C. 4.88 moles hydrogen; 60.3 grams zinc D. 1.22 moles hydrogen; 60.3 grams zinc

Answer 296

B. 2.44 moles hydrogen; 40.6 grams zinc

Question 297

Calculate the mass of titanium in kilograms in 0.4011 million grams of TiCl 4

Answer 297

101

Question 298

Calculate the mass of titanium in kilograms in 0.4011 million grams of TiCl4

Answer 298

0.870 g

Question 299

The two Br isotopes 79 Br and 81 Br, each has a natural abundance of about 50%. Determine what is the likely molecular weight of Br2. A. 162 amu B. 158 amu C. 160 amu D. All are equally like

Answer 299

C. 160 amu You can also refer to the periodic table.

Question 300

Determine the number of grams of C2H5N that will heat with 81.81 g of oxygen in the equation: C2H5N + O2 → CO + H2O + NO

Answer 300

40g

Question 301

When 12 grams of carbon (s) are mixed with 64.2 grams of O2 (g), calculate how many grams of CO2 will be formed: A. 12 grams CO2 B. 32 grams CO2 C. 64 grams CO2 D. 44 grams CO2

Answer 301

D. 44 grams CO2

Question 302

Determine the volume of carbon dioxide in cubic feet occupied by 120 lbs at a pressure of 1.5 atm.

Answer 302

750

Question 303

The element that is in Group 14 and the fourth period is: a. Germanium b. Gallium c. Iron d. Manganese

Answer 303

a. Germanium

Question 304

Determine the number of neutrons of the radioactive isotope C14. A. 14 B. 6 C. 8 D. 12

Answer 304

C. 8

Question 305

Author of Octet Rule

Answer 305

Gilbert Lewis

Question 306

The theory of resonance was developed by __ in order to further explain the bonding structures of molecules or ions not covered by the Lewis Octet rule. A. Alfred Nobel B. Linus Pauling C. Le Chatelier D. Emmanuel Kroop

Answer 306

B. Linus Pauling

Question 307

Which compound is formed by the reaction of malonic acid and urea with a catalyst, as discovered by Adolf von Baeyer?

Answer 307

Barbituric Acid

Question 308

Who discovered EDTA?

Answer 308

Ferdinand Munz

Question 309

The Nobel Prize for radioactivity discovery was shared between Curie and Roentgen. Who coined the word “Serendipity” in 1754?

Answer 309

Horace Walpole

Question 310

Who invented vulcanized rubber?

Answer 310

Charles Goodyear

Question 311

Who discovered the structure of benzene?

Answer 311

Friedrich August Kekule

Question 312

Who is the father of Quantum Theory?

Answer 312

Max Planck

Question 313

Who discovered x-ray?

Answer 313

Wilhelm Conrad Roentgen

Question 314

What was Melvin Calvin was known for his study of?

Answer 314

photosynthesis

Question 315

Who discovered Deuterium?

Answer 315

Harold C. Urey

Question 316

Father of nuclear chemistry and discovered proof of nuclear fission.

Answer 316

Otto Hann

Question 317

Who discovered carbon dating?

Answer 317

Willard Libby

Question 318

In an experiment it was found that the total charge on an oil drop was 5.93x10 -18 C. How many negative charges does the drop contain? A. 18 B. 23 C. 44 D. 37

Answer 318

D. 37

Question 319

Who won the Nobel Peace Prize for nuclear fission?

Answer 319

Otto Hahn

Question 320

Question situation: Find half life between A and B

Answer 320

Half life of A and B are the same

Question 321

The difference between the actual property value of a solution and the value it would have as an ideal solution at the same T and P and composition is called: A. Residual B. Partial Property C. Excess D. Gibbs Free Energy

Answer 321

C. Excess

Question 322

The element neon was discovered by A. Marks and Howell B. Travers and Ramsey C. Davy and Russel D. Pontina and Berzelius

Answer 322

B. Travers and Ramsey

Question 323

What other particle is formed in the fusion of two protons to yield deuterium?

Answer 323

neutron

Question 324

Which isotope is produced when Polonium-216 decays by emitting an alpha particle followed by two beta particles?

Answer 324

Polonium-212

Question 325

Process of breaking down a large isotope into smaller isotopes. A. nuclear fission B. beta particle emission C. nuclear fusion D. gamma ray emission

Answer 325

A. nuclear fission

Question 326

When a thorium-230 atom undergoes alpha decay, the products of the reaction are usually: A. Radium and an alpha particle B. Actinium and an alpha particle C. Actinium and a positron D. Radium and a positron

Answer 326

A. Radium and an alpha particle

Question 327

Determine how many milligrams of rubidium-84 remains after 99 days from a ten mg sample. The half life is 33 days. A. 2.50 mg remains B. 5.00 mg remains C. 0.10 mg remains D. 1.25 mg remains

Answer 327

D. 1.25 mg remains

Question 328

Determine the number of days it will take for one milligram of rubidium to decay to 0.6 mg. A. 132 B. 98 C. 63 D. 211

Answer 328

C. 63 Ru half life = 85.49 d

Question 329

Determine the decay product of americium 241 and the percentage remaining of the original americium after one thousand years. It is given that americium 241 has a half-life of approximately 432 years is known to be an alpha emitter. A. Neptunium 237; 25% B. Tritium 6; 65% C. Berkelium 246; 85% D. Bismuth 209; 45%

Answer 329

A. Neptunium 237; 25%

Question 330

Calculate how much ten milligrams of iodine 131/53 will be found in the body of a patient after 32 days (the half-life of iodine 131/53 is 8 days).

Answer 330

0.625

Question 331

Analyze and determine the mass weight in milligrams of a 2.01mg sample of an isotope 83-Bi has a half-life of 1.03 yrs that has not decayed after 3.77x10 3 hrs.

Answer 331

1.5 mg

Question 332

As a result of the Aykhal Crystal Denotation in 1974 (in the former Soviet Union), cesium-137 was measured (in 1993) in the soil concentration of 2x104 Bq/kg soil. If the background concentration of 137 Cs is 0.5 Bq/kg soil, how many years will it take before the concentration of 137 Cs reaches background levels? The decay of radionuclide occurs by a first-order reaction. Half-life is 30 years.

Answer 332

459 years

Question 333

An accident occurred in the Bataan nuclear power plant when it was being commissioned 30 years ago, 48.01 grams of tritium was released. If the half-life of tritium is 12.3 years, what was the mass of tritium left after the 12.3 years and at the end of 49 years.

Answer 333

24.0, 3.0 mg

Question 334

Draw the condensed and skeletal structures of diethyl ether which is used by most doctors and hospitals as an anesthetic during operations. A.C2H5OC2H5 B.C6H6O6 C.C5H10O D.CH3CH2OCH2CH3

Answer 334

D.CH3CH2OCH2CH3

Question 335

It is an organic reaction that converts an alcohol into an alkyl chlorine using triphenylphosphine and carbon tetrachloride.

Answer 335

Appel Reaction

Question 336

What compound can be used to convert alcohol or a phenol into an ester? A. Acetic anhydride: CH3-C-O-COCH3 B. Benzamide C. Maleic anhydrate: CH3-CH2-COO-CH3 D. Aqueous bromine solution

Answer 336

A. Acetic anhydride: CH3-C-O-COCH3

Question 337

Which of the following is a primary application of ethylene? A. Production of plastics and synthetic fibers B. Use as a plant hormone for ripening of fruits C. Use as a fuel in industrial applications D. Use as a refrigerant in cryogenic applications

Answer 337

B. Use as a plant hormone for ripening of fruits

Question 338

What is the buckyball? A. An epoxy resin B. C60H+++ C. A fullerene D. Sodium benzoate

Answer 338

C. A fullerene

Question 339

Adrenaline is produced in the body through a biochemical nucleophilic substitution reaction where: A. The leaving groups are larger and more complex than the halogen atoms frequently in nucleophilic substitution reactions. B. According to Markovnikov’s rule, the biosynthesis of epinephrine adds hydrogen atoms to the double banded carbon atom. C. The nucleophilic nitrogen atom of norepinendrine from a covalent bond with the CH3 of S adenosylmethionine D. The reactant neocleophile atom replaces the leaving group in the nucleophylic substitution reaction.

Answer 339

D. The reactant neocleophile atom replaces the leaving group in the nucleophylic substitution reaction.

Question 340

What organic product is formed when C6H5CH2COOH is treated with CH3OH + H2SO4 (catalyst)? A. C6H5CH2CH2OH B. C6H5CH2C00-Na+ + CO2 + H20 C. C6H5CH2C00-NH4 D. C6H5CH2CO2CH3 + H20

Answer 340

D. C6H5CH2CO2CH3 + H20 Fischer esterification

Question 341

In a dehydration reaction where water is lost, an organic compound C3H8O reacts with concentrated phosphoric acid and a product is formed. This product rapidly decolorizes a solution of bromine in tetrachloromethane. What is this product?

Answer 341

Propene

Question 342

The person’s sense of smell and taste depend on specific biochemic receptors present in a person’s nose and mouth. In 2004, a Nobel Prize was given to the researchers who established this fact and identified the the type of organic compound associated with the sense of smell and taste. The chemical identified was;

Answer 342

rhodopsin

Question 343

Name the major physiologically active substances that comes from: bark of the willow tree, the pituitary gland, the sap of the poppy and the belladenna plant. A. Cocaine, reserpine, salicin, atropine B. Reserpine, atropine, B-endorphine, opium C. Opium, cocaine, salicin, and reserpine D. Salicin, beta-endomorphin, opium, atropine

Answer 343

D. Salicin, beta-endomorphin, opium, atropine

Question 344

It is the major component of lecithin.

Answer 344

Phosphatidylcholine

Question 345

Taurine, a Beta amino acid belongs to the acidic group of: A. –SO2OH B. –COONH3 C. –COOH D. –C=OH

Answer 345

A. –SO2OH

Question 346

In the study of fats and lipids, determine which of the two triglycerides has a higher melting point? Substance A containing only lauric acid and glycerol, or substance B-containing only stearic acid and glycerol? A. Both have the same melting points B. B C. A D. None of these

Answer 346

B. B

Question 347

Calculate the degree of deprotonation of the side chain of cysteine at pH 7.30, given that the side chain –SH group has pKa = 8.20.

Answer 347

0.11 pH = pKa - log (1-X/X). Find X

Question 348

Radioactive solid nuclear wastes are disposed off by A. high temperature incineration B. pyrolysis C. pathological incineration D. underground burial in concrete containers

Answer 348

D. underground burial in concrete containers

Question 349

A contaminated soil is to be excavated and treated in a completely mixed aerated lagoon at a Superfund site. To determine the time it will take to treat the contaminated soil, a laboratory completely mixed batch reactor is used to gather the following data. Determine the time to achieve 99% reduction in the original concentration.

Answer 349

92 days May missing table here. Memorise the answer.

Question 350

Calculate the theoretical oxygen demand of glutamic acid. Assume the concentration of glutamic acid is 0.1 mM.

Answer 350

21 mg/L Glutamic Acid - C5H9O4N Get CBOD from: C5H9O4N + 4.5O2 -> 5CO2 + 3H2O + NH3 Get NBOD from: NH3 + 2O2 -> NO3- + H+ + H2O TBOD = CBOD+NBOD

Question 351

Compute the theoretical NBOD of a wastewater containing 30 mg/L of ammonia as nitrogen. If the wastewater analysis was reported as 30 mg/L of ammonia (NH 3 ), what would the theoretical NBOD be?

Answer 351

137 mg/L and 113 mg/L NH3+ 2O2→NO3-+ H2O + H+ Use Stoich

Question 352

A sample of municipal sewage is diluted to 1% by volume prior to running a BOD5 analysis. After 5 days the oxygen consumption is determined to be 2.00 mg/L. What is the BOD5 of the sewage?

Answer 352

200 mg/L

Question 353

If the BOD of a municipal wastewater at the end of 7 days and 250 C is 60.0 mg/L and the ultimate BOD is 85.0 mg/L, what is the rate constant at 160 C? A. 0.08/d B. 0.22/d C. 0.11/d D. 0.30/d

Answer 353

A. 0.08/d

Question 354

The following data are provided to you: Seeded wastewater: Initial DO = 8.6 mg/L Final DO (after 5 d) = 2.1 mg/L Volume of wastewater = 2.5 mL Total volume in BOD bottle = 300 mL Seeded dilution water: Initial DO = 8.6 mg/L Final DO (after 5 d) = 7.3 mg/L Temperature = 200 C Calculate the BOD of the sample in mg/L. A. 598 B. 625 C. 760 D. 832

Answer 354

B. 625

Question 355

If a water sample was found to contain 19.2 mg/L of magnesium ion and 44.4 mg/L of calcium ion, expressed the amount of hardness. The sample case from a Maynilad source.

Answer 355

189 mg/L as CaCO3

Question 356

A landfill with a gas collection system is in operation and serves a population of 200,000. MSW is generated at a rate of 1.95 kg · (capita) −1 · day−1 . Gas is produced at an annual rate of 6.2 L · kg −1 of MSW delivered to the landfill. The gas contains 55% methane. Gas recovery is 15% of that generated. The heat content of the landfill gas is approximately 17,000 kJ · m −3 (a value lower than the theoretical value because of dilution of the methane with air during recovery). The landfill company and a developer have proposed to build a subdivision in the vicinity of the landfill and pipe the methane generated to the homes to be used for heating. The homes are estimated to use an average of 110 × 10 6 kJ of heat energy each year. Peak usage during winter is 1.5 times the average usage. How many homes can be built in the subdivision?

Answer 356

7 homes

Question 357

A power plant in Benguet is burning coal on a cold clear January at 8:00 am with a wind speed of 2.6 meters/second measured at an elevation of 31 meters and an inversion layer with its base founded at a height of 695 meters. The effective height of the stack is 31 meters. Calculate the distance downward wt which the plume released will reach the inversion layer and start to mix downward

Answer 357

5.8 km

Question 358

Determine the area required for anew landfill in Batangas province with projected life of 30 years for a population of 250000 people generating 2.10 kg per capita per day. The density of the compacted waste is 472 kilograms per cubic meter. The height of the landfill should not exceed 16 meters.

Answer 358

78 ha

Question 359

The Tanay Rizal Stone Works employs six workers who produce uncompacted waste from the products formed for building decors. If the density of the uncompacted waste is 480 kilograms per cubic meters, determine the annual volume of solid waste produced by the factory assuming a waste generation volume rate of one kilogram per capita per day.

Answer 359

4.56

Question 360

The Malayan landfill about 100 kilometers from Kuala Lumpur serves a population of 562,400 people generating MSW at a rate of 1.90 kilograms per capita per day. The capacity of the landfill is 11.3x10 6 cubic meters. In 2015, 63% of the landfill was being used. The ratio of cover to compacted fill is 1.95. Calculate the remaining projected life for the landfill. Assume the density of the compacted waste to be 492 kilograms per cubic meters.

Answer 360

2.76 years

Question 361

A town of 20,000 in Laguna generates 0.96 kg/(capita)-day of MSW. A town of the same size in the Makati City in Metro Manila generates 1.9 kg/(capita)-day of MSW. How much MSW is generated in each town? How many trucks would be needed to collect the waste twice weekly? The trucks each have a capacity of 4.5 MT and operate 5 days per week. Assume that the trucks average two loads per day at 75% capacity. Calculate the number and volume of MSW in tons that enter the landfill

Answer 361

19100 kg/d and 39000 kg/d, 4 and 8 trucks, 58 m3 /d 105 m3 /d

Question 362

A municipal landfill has available space of 16.2 ha at an average depth of 10 m. Seven hundred sixty-five (765) cubic meter per day of solid waste is dumped at the site 5 days a week. This waste is compacted to twice its delivered density. Draw a mass-balance diagram and estimate the expected life of the landfill in years.

Answer 362

16 years

Question 363

A deer eats 25 kg of herbaceous material per day. The herbaceous matter is approximately 20% dry matter (DM) and has an energy content of 10 MJ/(kg DM). Of the total energy ingested per day, 25% is excreted as undigested material. Of the 75% that is digested, 80% is lost to metabolic waste products and heat. The remaining 20% is converted to body tissue. Calculate the percentage of energy consumed that is converted to body tissue. A. 15% B. 20% C. 19% D. 24%

Answer 363

A. 15%

Question 364

Analyze and calculate the percentage of nickel in a 1.201g sample of nickel ore which was analyzed by the volumetric method. A solution of 48mL containing 1.4x10 -2 g of KCN/mL and the excess cyanide required half a milliliter of silver nitrate solution with 1.25x10 -2 g AgNO 3 per milliliter.

Answer 364

12.5%

Question 365

You are working in a site where a leaking underground storage tank has contaminated the soil and groundwater was analyzed and the concentrations of benzene and methyl tertiary butyl ether (MTBE) were found to be 45 and 500 micro grams per liter, respectively. At the soil temperature (100 C) the dimensionless Henry’s constants, H for benzene and MTBE are 0.09 and 0.01, respectively. Calculate the soil vapor concentrations of both chemical compounds.

Answer 365

Benzene = 0.36 micro g/L and MTBE = 5 micro g/L C benzene= H × C*_benzene C MTBE= H × C*_MTBE

Question 366

A solution of calcium chloride is prepared in a 1 L volumetric flask. A 60-g sample of CaCl 2 is added to a small amount of water in the flask, and then additional water is added to bring the total volume of the solution to 1 L. What is the concentration of calcium chloride in units of molarity?

Answer 366

0.5406 M

Question 367

A solution of cation gives a crimson red flame. This flame test is a confirmatory test for: a. Sr2+ b. K+ c. Mn2+ d. Ca2+

Answer 367

a. Sr2+

Question 368

What is the color of nickel chloride? a. white b. blue c. red d. yellow

Answer 368

d. yellow

Question 369

Substances whose solutions change color due to changes in pH.

Answer 369

Indicator

Question 370

Determine the number of moles of an unknown base in a solution when titrated with 0.150 M HCl and 22.01ml of acid were needed to reach the end point of the titration.

Answer 370

3.30x10 -3ml Stoich

Question 371

Determine the pH of 0.21 M solution of sodium benzoate in water at room temperature.

Answer 371

8.74 Ka = 6.3x10-5 pH = pKa - log (X^2/0.21-X)

Question 372

In a standard chemical reaction, rate is governed by the relationship rate=pze-E/RT, where p and z refer to the probability that reacting molecules make a favorable encounter. To increase the probability of reaction, enzymes are employed. Based on the above equation, if E is the activation energy, which is more favorable and why? A lower or hgher E? A. Lower E so that more molecules possess sufficient energy to react B. Higher E so that a better nucleophile and electrophile are catalyzed C. Lower E so that a proton can be donated or stolen for the reactants leading to better catalysis D. Higher E so the bonds of the reactants will be strained and provide more power transition state condition

Answer 372

C. Lower E so that a proton can be donated or stolen for the reactants leading to better catalysis

Question 373

The coexistence curve where the plot of pressure versus temperature along which the two phases coexist was shown by ClausiusClapeyron. What did Clausius postulate? A. The Clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molar volume of the liquid VL in comparison with the molar volume of the gas VG B. The Clausius-Clapeyron equation does not apply to this situation C. The Clausius-Clapeyron theory is applicable only for vaporization and sublimation condition D. Both scientists apply their postulates to linear and curvilinear representation

Answer 373

A. The Clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molar volume of the liquid VL in comparison with the molar volume of the gas VG

Question 374

What is the significance of colligative property in physical chemistry? a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute b. It refers to the temperature, pressure and energy of fusion of volatile solutes in phase equilibrium c. It refers to the non-existence of pressure among molecules within the solute d. It refers to the temperature differentials exhibited by non-volatile solutes in reactions

Answer 374

a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute

Question 375

In the collision theory of chemical kinetics, it is suggested that reaction rate is governed by the relationship rate=Pze-E/RT. What can an enzyme do to the activation energy of the reaction E? A. Enzymes can raise temperature to make the reaction proceed faster B. None of these C. Enzymes bind the reactants in close proximity for a longer period in order to get the reaction energy going D. Enzymes provide an alternative reaction pathway in lowering the energy level of the reaction

Answer 375

D. Enzymes provide an alternative reaction pathway in lowering the energy level of the reaction

Question 376

What is the theory in two or three dimensional collision to be applied when playing billiard balls and in order to sink the target ball in the corner pocket? A. The center of the mass theory where the center of the mass of the system moves as all the mass in the system were concentrated at that point, and one of them is initially at rest, and they were in perpendicular direction of the collision B. Proton-proton elastic collision C. The component of momentum an isolated system in each of the directions (x, y, z) are conserved independently D. Where two equal masses undergo a glancing elastic collision

Answer 376

D. Where two equal masses undergo a glancing elastic collision

Question 377

When travelling at NLEX at 80mph, a stopped car in front causes you to suddenly skid to stop. What happened to the kinetic energy of the moving car? A. Some of it were converted to internal energy and some transferred to the road and surroundings B. It was transferred to the internal energy of the road C. All of it transferred to the road and surroundings D. All of it are still in the car

Answer 377

B. It was transferred to the internal energy of the road

Question 378

Using the van der Waals, derive the equation for (dH/dP) T for van der Waals gas and estimate (dH/dP) T for CO 2 (g) in J/barmol when the temperature is at 300 K given the data a = 3.64 L2 /bar/mol/mol and b = 0.042 L/mol.

Answer 378

b-2a/RT; -25

Question 379

Consider the following reaction: C3H8 (g) + 5 O2 (g) = 3 CO2 (g) + 4 H2O (g) ∆H = -2202 kJ Which of the following applies to a forward reaction? A. entropy – increases, enthalpy – decreases B. entropy – increases, enthalpy – increases C. entropy – decreases, enthalpy – decreases D. entropy – decreases, enthalpy – increases

Answer 379

A. entropy – increases, enthalpy – decreases

Question 380

Assume that the following exothermic reaction is at equilibrium: H2 (g) = I2 (g) + 2HI(g) Tell whether the position of equilibrium will shift to the right or the left if we (1) Remove some HI (2) Add some I2 (3) Remove some I2 (4) Increase the temperature (5) Add a catalyst A. right, left, left, right, no shift B. left, left, right, right, no shift C. right, right, left, right, right D. right, right, left, left, no shift

Answer 380

D. right, right, left, left, no shift Typo: H2 + I2 = 2HI Exothermic: right dxn - add reactants Endothermic: left dxn - add reactants

Question 381

In a study of the equilibrium H2 + I2 = 2HI 1 mol of H2 and 3 mol of I2 gave rise at equilibrium to x mol of HI. Addition of a further 2 mol of H2 gave an additional x mol of HI. What is K at the temperature of the experiment? A. 3 B. 4 C. 5 D. 6

Answer 381

B. 4 1 mol + 3 mol

Question 382

The equilibrium constant for the reaction below is 20.0 at 40.0 °C: H2 + I2 = 2HI The vapor pressure of solid iodine is 0.10 bar at that temperature. If 12.7 g of solid iodine are placed in a 10- dm3 vessel at 40.0 °C, what is the minimum amount of hydrogen gas that must be introduced in order to remove all the solid iodine? A. 0.012 mol B. 0.027 mol C. 0.044 mol D. 0.063 mol

Answer 382

D. 0.063 mol Use PV=nRT then stoich

Question 383

Consider three identical flasks filled with different gases at 273. 15 K Flask A: CO at 760 mmHg Flask B: N2 at 250 mmHg Flask C: H2 at 100 mmHg All of the following statements are incorrect except A. Flask B gas molecules will have the greatest root mean square velocity B. Flask C will have the greatest average kinetic energy. C. Flask A gas molecules will have the least number of collisions per second with the container walls. D. Flask C gas molecules will have the greatest root mean square velocity.

Answer 383

B. Flask C will have the greatest average kinetic energy.

Question 384

A 10.0 ml sample of wastewater with enough water to fill a 300 ml bottle has an initial DO of 9.0 mg/L. To help assure an accurate test, it is desirable to have at least a 3.0 mg/L drop in DO during the five-day run, and the final DO should be at least 3 mg/L. For what range of BOD5 would this dilution produce the desired results. Assume this test to be a five-day, unseeded BOD test. A. 60-190 B. 70-150 C. 90-180 D. 80-170

Answer 384

C. 90-180 Use BOD5=[DOi-DOf]/P

Question 385

A standard 5-Day BOD test is run using a mix consisting of three parts of distilled water and one- part wastewater. If the initial dissolve oxygen of the mix is 10 mg/L and after 5 days, the dissolved oxygen is 4 mg/L. The dissolved oxygen value after a long period of time is constant at 1 mg/L. Calculate the rate constant, k (day-). a. 0.22/d b. 0.24/d c. 0.25/d d. 0.23/d

Answer 385

a. 0.22/d Use BOD5 then get P

Question 386

A standard BOD test is run using seeded dilution water. In one bottle, the waste sample is mixed with seeded dilution water giving a dilution of 2:30. Another bottle, the blank, contains seeded dilution water. Both bottles begin the test with DO at the saturation value of 9.2 mg/L. After five days, the bottle containing waste has DO equal to 2.0 mg/, while that containing just seeded dilution water has DO equal to 8.0 mg/L. Find the five-day BOD of the waste. A. 88 B. 72 C. 65 D. 91

Answer 386

D. 91 Calculate P then use BOD5 formula.

Question 387

Just below the point where a continuous discharge of pollution mixes with a river, the BOD is 10.9 mg/L, and DO is 7.6 mg/L. The river and waste mixture has a temperature of 20degC, a deoxygenation constant of 0.23/day, an average speed of 0.3 m/s, and an average depth of 3 m. Find the minimum value of DO if DOs = 9.1 mg/L. A. 5.7 B. 4.4 C. 6.0 D. 7.1

Answer 387

A. 5.7 Use Crit Time eqn where kr=/kd

Question 388

An appropriate empirical formula for bacterial cells is C5H7O2N. What would be the theoretical oxygen demand (mg/L) for 1 g of such cells? A. 1620 B. 1980 C. 1130 D. 1570

Answer 388

B. 1980 Use stoich using the eqn: C5H7O2N + 5O2 -> 5CO2 + 2H2O + 2NH3 NH3 + 2O2 -> NO2- + H+ + H2O

Question 389

The oxygen sag caused by a cannery reaches a minimum DO equal to 3 mg/L. Upstream from the cannery, the river DO is saturated at 10 mg/L and it has no BOD of its own. Just downstream from the discharge point, the DO is still essentially saturated (i.e. consider initial deficit to be zero so the downstream deficit is proportional to the initial BOD). By what percentage should the BOD of the cannery waste be reduced to assure a healthy stream with at least 4 mg/L DO everywhere? A. 19 B. 11 C. 14 D. 17

Answer 389

C. 14 DO_max = DO_sat - DO_min % = (desired DOmax/orig DO max) required BOD = 100% - %

Question 390

A wastewater treatment plant discharges 1.0 m3/s of effluent having an ultimate BOD of 40 mg/L into a stream flowing at 12.0 m3 /s. Just upstream from the discharge point, the stream has an ultimate BOD of 3.0 mg/L. The deoxygenation constant kd is estimated at 0.23/day. Assuming a constant cross-sectional area for the stream equal to 55 m2, what BOD would you expect to final at a point 10,000 m downstream? A. 5.2 B. 7.3 C. 6.5 D. 4.8

Answer 390

A. 5.2 Use L0=[QwLw+QrLr]/[Qw+Qr]

Question 391

A water softener has 0.07 m3 of ion exchange resin with an exchange capacity of 46 kg/m3. The water use is 1500 L/day. If the incoming water contains 245 mg/L of hardness as CaCO3 and the softened water needs to be 100 mg/L as CaCO3, what is the time (in days) between regeneration cycles? A. 10 B. 15 C. 12 D. 18

Answer 391

B. 15 Soln: Stoich

Question 392

Waxes are A. Triglyceride B. Fatty acids alcohol esters C. Alkyl sulfonates D. Salts of fatty acids

Answer 392

B. Fatty acids alcohol esters

Question 393

The rate of nucleophilic substitution reaction of tert-butyl bromide with OH– is found to be independent of the concentration of OH– at any instant. It can be inferred that the reaction is: A. First-order (SN1) B. Zero-order C. Second-order (SN2) D. Pseudo-first-order

Answer 393

A. First-order (SN1)

Question 394

Which of the following is true about SN1 reactions of alkyl halides (RX)? A. A trigonal-bipyramidal transition state is formed after the nucleophile attacks the carbon attached to X B. A two-step reaction mechanism (slow step and fast step) is involved. C. The overall reaction follows a second-order kinetics. D. All of these

Answer 394

B. A two-step reaction mechanism (slow step and fast step) is involved.

Question 395

Trimethyl-n-propylammonium is heated with KOH to yield N,N,N-trimethylamine and: A. Propane B. 2-Propanol C. n-Propanol D. Propene

Answer 395

D. Propene

Question 396

Reduction of ethyl cinnamate using LiAlH4 produces the alcohol: A. 3-phenylprop-2-en-1-ol B. 2-phenylprop-2-en-2-ol C. 3-cyclohexylprop-2-en-1-ol D. 2-cyclohexylprop-2-en-2-ol

Answer 396

A. 3-phenylprop-2-en-1-ol

Question 397

Styrene undergoes ozonolysis to yield two carbonyl compounds. Which of the following pairs is produced by this reaction? A. Formaldehyde and benzoic acid B. Benzoic acid and carbonic acid C. Acetone and benzaldehyde D. Benzaldehyde and formaldehyde

Answer 397

D. Benzaldehyde and formaldehyde

Question 398

In which reaction of alkyne can keto-enol tautomerism exist? A. Markovnikov hydrohalogenation B. Catalytic hydrogenation C. Acid-catalyzed hydration D. Ozonolysis

Answer 398

D. Ozonolysis

Question 399

Which of the following compounds is not aromatic? A. Penanthrene B. Anthracene C. Hydroquinone D. Tetrahydrofuran

Answer 399

D. Tetrahydrofuran

Question 400

Which of the following characteristic enzymes of gluconeogensis is not found in the cytosol? A. Pyruvate carboxlyase B. Fructose-,6-bisphosphatase C. Any of these D. Glucose-6-phosphatase

Answer 400

A. Pyruvate carboxlyase

Question 401

Chylomicrons are synthesized in A. blood B. liver C. intestine D. pancreas

Answer 401

C. intestine

Question 402

Palmitate has 16 carbon atoms with A. 2 double bonds B. 3 double bonds C. One double bond D. None of these

Answer 402

D. None of these

Question 403

Who discovered vitamin C (ascorbic acid)? A. Paul Berg B. Linus Pauling C. Albert Szent-Gyorgyi D. Kerry Mull

Answer 403

C. Albert Szent-Gyorgyi

Question 404

With an increase in pressure in gaseous phase chemical reactions, the fractional conversion __________ when the number of moles decreases. A. increases B. decreases C. remains unaffected D. unpredictable from the data

Answer 404

A. increases

Question 405

Vitamin K1 was first isolated from alfalalfa and has the phytyl side chain consisting of A. four isoprene units B. six isoprene units C. nine isoprene units D. four isoprene units

Answer 405

A. four isoprene units

Question 406

A ketogenic amino acid is one which degrades to keto-sugars A. either acetyl CoA or acetoacetyl CoA B. pyruvate or citric acid cycle intermediates C. multiple intermediates including pyruvate or citric acid cycle D. intermediates and acetyl Co or acetoacetyl CoA

Answer 406

B. pyruvate or citric acid cycle intermediates

Question 407

Reaction of benzene with chlorine gas to produce tri-chlorobenzene exemplifies a/an __________ reaction. A. elementary B. parallel C. autocatalytic D. series

Answer 407

D. series

Question 408

In the normal breakdown of phenylalanine, it is initially degraded to A. fumarate B. tyrosine C. lysine D. phenylpuruvate

Answer 408

B. tyrosine

Question 409

Which of the following amino acids can form hydrogen bonds with their side (R) groups? A. Asparagine B. Aspartic acid C. Glutamine D. All of these

Answer 409

D. All of these

Question 410

Why does the use of sunglasses with adjustable shading a practical illustration of the Le Chatelier’s principle? (Silver chloride is the compound used in the glasses, which upon exposure to sunlight produces silver Ag and chlorine Cl2). A. Any of these B. The addition of energy in the form of sunlight drives the equilibrium to the right and its removal drives the equilibrium to the left, since the more metal is produced, the darker the glasses; C. When external stress is applied to a system in equilibrium, which in this case refers to the production of silver metal which causes a change in the shade of the sunglasses. D. The changes in temperature cause the exothermic or endothermic reaction of the silver metal production to shift from left to right or vice-versa, thus causing the shades to change.

Answer 410

A. Any of these

Question 411

Adrenaline is produced in the body through a biochemical nucleophilic substitution reaction where: a. The leaving groups are larger and more complex than the halogen atoms frequently in nucleophilic substitution b. According to Markovnikov’s rule, the biosynthesis of epinephrine adds hydrogen atoms to the double banded c. The nucleophilic nitrogen atom of norepinendrine from a covalent bond with the CH3 of S adenosylmethionine d. The reactant neocleophile atom replaces the leaving group in the nucleophylic substitution reaction.

Answer 411

c. The nucleophilic nitrogen atom of norepinendrine from a covalent bond with the CH3 of S adenosylmethionine

Question 412

A chemical plant chemist working in the Pasig River Area was given the task to determine which of the two acid solutions can be discharged to the Pasig River with minimal effect on the river water. The chemist analysed 0.1M solutions of the acetic acid (HAc) with Ka of 1.81 x 10^-5 and hydrofluoric acid (HF) with Ka of 6.6 x 10^-4. Which acid solution can be discharged? A. HF B. HAc C. combination of both D. Not applicable

Answer 412

B. HAc Higher pKa, not very acidic and thus safer

Question 413

A farmer has a 7-year rotation of corn, soybeans, and wheat and 4 years of alfalfa. Manure will be applied before corn and wheat and before seeding to alfalfa. The initial soil test results indicate total phosphorus level of 48 kg P · hectare −1 . Manure is to be surface-applied in mid-March and disk-incorporated within 2 days of application. One-third of the organic nitrogen and 50% of the nitrogen from NH 4 is available to the corn crop. To obtain the desired yield of corn, the local extension agent has told the farmer to apply 100 kg of nitrogen per hectare. A. 5gN/kg manure; 20000 g manure/ha B. 36gN/kg manure; 60000 g manure/ha C. 18gN/kg manure; 30000 g manure/ha D. 5gN/kg manure; 15000 g manure/ha

Answer 413

5Gn/kg manure; 20000 g manure/ha gN/kg = 12(1/3) + 6(0.5) kg/ha = 100*1/5*1000g/kg

Question 414

If a 1.0 m3 s-1 flow water treatment plant uses ten sedimentation basins with an overflow rate of 15m3 day-1 m-2, what would be the surface area (m2) of each tank?

Answer 414

5.76 m2 Qv = v * A A = 10/15 * (3600*24 s/d)

Question 415

Sherwood Roland and Mario Molina’s work on stratospheric ozone depletion garnered them the 1995 Nobel Prize in Chemistry. Which among the following species did they determine act as a catalyst for the decomposition of ozone? A. Refrigerants B. CClF3 C. Nitrogen Oxides D. Chlorine Atoms

Answer 415

D. Chlorine Atoms Cl atoms from CFCs worsens O3 depletion

Question 416

Which scientist is best known for his work on the role of nitrogen oxides (NOx) in ozone depletion? (A) Sherwood Rowland (B) Mario Molina (C) Paul Crutzen (D) Harold Johnston

Answer 416

(C) Paul Crutzen

Question 417

As part of your inheritance, an antique wristwatch was bestowed upon you. After keeping it for one year and 6 months, you were informed that the dials were painted using pigments containing radioactive radium. Analysis showed that the dials had an activity of 0.5 counts per second of beta particles. If 1 microcurie exhibits a dosage of 1000 mrem per year, what would be your accumulative equivalent dose during your exposure when you were unaware of its radioactivity? A. 0.0135 mrem B. 0.0203 mrem C. 0.0305 mrem D. 0.0458 mrem

Answer 417

A. 0.0135 mrem 0.5 count/s(1 Ci/3.7x10^10 count/s)(10^6 uCi/Ci)(1000 mrem/yr / 1 uCi)

Question 418

A manufacturing plant in Laguna that produces boron-based additives is sourcing minerals to use as raw materials for their process. Their standard run utilizes kernite as the source material. Due to the shortage of the aforementioned mineral, the Purchasing Department sourced borax instead. How much additional borax in kg must be processed in order to maintain the 1 MT Boron produced in a standard run of Kernite? A. 283 kg B. 717 kg C. 2495 kg D. 6320 kg

Answer 418

C. 2495 kg Kernite: Na2B4O7-4H2O Borax: Na2B4O7-10H2O Stoich to get Kernite Reqd and Borax Rqd. Answer = Borax Rqd - Kernite Rqd

Question 419

Determine the percent atom economy of the Raschig Process. A: 17.3% B: 22.4% C: 34.7% D: 46.5%

Answer 419

A: 17.3% Raschig Process: Hydrazine Production 2NH3 + Cl2 + 2NaOH -> N2H4 + 2NaCl + 2H2O %atom economy = stoic mass desired product/stoich mass reactants

Question 420

Which scientist is best known for his contributions to the discovery of iodine-131 and 10 other elements? (A) Marie Curie (B) Enrico Fermi (C) Glenn T. Seaborg (D) Albert Einstein

Answer 420

(C) Glenn T. Seaborg

Question 421

Which radioactive isotope is used to scan the whole body for tumors? (A) 51-Cr (B) Ga-67 (C) Se-75 (D) Kr-81m

Answer 421

(B) Ga-67

Question 422

Which radioactive isotope is used to scan the pancreas? (A) 51-Cr (B) Ga-67 (C) Se-75 (D) Kr-81m

Answer 422

(C) Se-75

Question 423

Which radioactive isotope is used to scan the lungs for ventilation? (A) 51-Cr (B) Ga-67 (C) Se-75 (D) Kr-81m

Answer 423

(D) Kr-81m

Question 424

Which radioactive isotope is used to diagnose albinism? (A) 51-Cr (B) Ga-67 (C) Se-75 (D) Kr-81m

Answer 424

(A) 51-Cr

Question 425

Glutamic acid is used as one of the reagents for a standard to check the BOD test. Determine the theoretical oxygen of 150 ppm of glutamic acid.

Answer 425

212 ppm

Question 426

Estimate the energy emitted per photon as well as the quantity of photons emitted per second from a 100W yellow light bulb with y=550nm and a 1KW microwave source with y=cm emitting 1.99×10^-23 J/photon and 5.03×1025photons/s. a) 3.6x10-19 /and 2.77×1020 photons/s b) 2.62×10-18J and 3.11×1021photons/s c) 3.91x10-20J and 4.22x1019photons/s d) 4.11×10-20J and 1.67×1020photons/s

Answer 426

a) 3.6x10-19 /and 2.77×1020 photons/s Only option that has product equal to 100W

Question 427

Write the chemical reaction for the deacetylation of acetyl-histone.

Answer 427

Histone-(CH2)4-NH3+ + CH3-COO- ↔ Histone-(CH2)4-NH-C(CH3)=0

Question 428

Find the degree of freedom for a saturated solution of salt in equilibrium with solid salt and water vapor

Answer 428

df = 1 df = 2-3+2 = 1

Question 429

What is the maximum mass of crude fluorite ore in metric tons, needed to make 2.42 metric tons of fluorine if the ore contains 70% calcium fluoride

Answer 429

7.2 2.42*(1/2)*(70/38)*(100/70) = 7.096 MT

Question 430

pKa of chloroacetic acid

Answer 430

2.85 look in periodic table

Question 431

When 1.61 × 10-3 moles of phenolphthalein indicators in dissolved in one liter of water plus ethanol, estimate the concentrations of [Hphth], [H3O+] and [phth-]. a. [Hphth] = 1.599 × 10-3 M; [H30*1 = 8.0 × 10-7 M, [phth-]= 8.0 × 10-7 M b. Hphth] = 0.913 × 105 M; [H30*] = 6.99 x 10-8 M, [phth-]= 6.72 × 10-6 M c. Hphth] = 1.512 x 10-4 M; [H30*] = 7.82 x 10-6 M, [phth-]= 6.07 x 10-6 M d. None of these

Answer 431

a. [Hphth] = 1.599 × 10-3 M; [H30*1 = 8.0 × 10-7 M, [phth-]= 8.0 × 10-7 M

Question 432

An experimental electric jeepney running in Makati on 12V battery at 20 m/s has a total energy storage of 2.0×10^7 Joules. If 8.0 KW is needed to move the vehicle, what is the quantity of energy supplied to the motor and how far will it travel? a. 500 A, 35km b. 960 A, 71km c. 814 A, 60km d. 667 A, 50km

Answer 432

d. 667 A, 50km P = VI I = P/V = 8000/12 = 667 A

Question 433

In normal blood, there are about 5.4x10^9 red blood cells per mL. The volume of a red blood cell is about 90x10-12cm3. and its density is 1.096g/mL. How many liters of whole blood would be needed to collect 0.5kg of red blood cells? a. 1.1L b. 0.92 c. 0.6L d. 2.1L

Answer 433

b. 0.92 Dim Analysis

Question 434

In a normal adult at rest the average speed of flow of blood through the aorta is 0.33m/s. The radius of the aorta is 9mm and the viscosity of blood at body temperature, 37°C, is about 4×10-3kg/m-s. Calculate the pressure drop along a 0.5m length of the aorta. a. 26Pa b. 43Pa c. 65Pa d. 77Pa

Answer 434

c. 65 Pa Use Hagen Pouiseuille Equation

Question 435

Of the following aqueous solutions, the one with the lowest freezing point is: a. 0.01m MgSO4 b. 0.011m NaCI C. 0.018m CH3CH2OH d 0.008m MgCl2

Answer 435

d 0.008m MgCl2 Concept: Freezing point depression

Question 436

A compound is 42.9% C, 2.4% H, 16.7% N, and 38.1% O by mass. Addition of 6.45g of this compound to 50mL of benzene (0.879g/mL, K- = 5.12K/m lowers the freezing point from 5.53 to 1.37°C. What is the molecular formula of this compound? a. C4H6NO4 b. C6H4N2O6 c. C6H6N4O2 d. C4H4N2O4

Answer 436

b. C6H4N2O6 Concept: Empirical Formula and Freezing Point Depression

Question 437

What is the value of the equilibrium constant K for the reaction between copper metal and ferric ion in aqueous solution at 25°C? The half-cell potentials E° Cu2+/Cu and E° Fe3+/Fe2+ are 0.34V and 0.771V, respectively. a. 4×10^14 b. 0.0441 c. 1553 d. 2.4x10^-11

Answer 437

a. 4×10^14

Question 438

Calculate the change in molar Gibbs free energy of liquid water treated as an incompressible fluid when the pressure is increased from bar to 2bar at 298K. a. 0.9J/mol b. 1.8J/mol c. 2.7 J/mol d. 3.6J/mol

Answer 438

b. 1.8 J/mol Concept: ΔG = VΔP = ΔP/ρ

Question 439

Determine the value of K from Kp = 14800 for the following reaction at 184°C: 2NO(g) + O2 (g) = 2NO2 (g) a. 6.74×105 b. 7.66×105 c. 4.35×102 d. 5.55×105

Answer 439

d. 5.55×105 Kc=Kp/[(RT)^Δng] Δng = mol g prod - mol g rxt

Question 440

A certain solid compound was tested in a laboratory and was analyzed to contain 6.5% hydrogen, 42.2% carbon, and 5.5% oxygen, with a molecular weight of approximately 341.2. Determine the chemical formula. a. C10H14016 b. C12H12O11 c. C6H12O6 d. C11H16O22

Answer 440

b. C12H12O11 Should be sucrose -> C12H22O11

Question 441

Biochemical compounds are either hydrophilic, hydrophobic, or amphipathic. Classify the following compounds: glucose, stearic acid, soaps, fatty acids A. Amphipathic, amphipathic, hydrophobic, hydrophobic B. Hydrophilic, hydrophobic, amphipathic, hydrophobic C. Hydrophilic, amphipathic, amphipathic, hydrophobic D. Hydrophobic, hydrophilic, hydrophobic, amphipathic

Answer 441

B. Hydrophilic, hydrophobic, amphipathic, hydrophobic Amphoteric -> both as acid + base Ampholyte -> w/ acidic+basic group

Question 442

Which element is difficult to remove from sewage and wastewater and at the same time, it contributes to bacterial and algae overgrowth in freshwater?

Answer 442

Nitrogen

Question 443

Which of the following is true about the closest packing of atoms? a. Tetrahedral voids are larger than octahedral voids. b. Tetrahedral voids are smaller than octahedral voids. c. Tetrahedral voids have same sizes as octahedral voids. d. None of these

Answer 443

b. Tetrahedral voids are smaller than octahedral voids. Coordination No. - No. of atoms in contact w/ each atom

Question 444

Types of radioactive decay

Answer 444

Alpha decay Beta decay Gamma decay Positron emission Electron capture

Question 445

In periodic table, which of the following is group considered a radioactive? a. Above 75 b. Above 83 c. Above 115 d. Between 80-100

Answer 445

b. Above 83 Those next to Pb

Question 446

Chymotrypsin is used for following protein as shown: Met - Tvr + Leu - Trp - GIv - Phe - Ser How many peptides can be formed after hydrolysis? a. 3 b. 4 c. 5 d. 6

Answer 446

b. 4 Chymotrypsin - aromatic amino acids (Tyr, Trp, Phe) Trypsin - basic amino acids

Question 447

Which of the following is a ceramide? a. sphingosine b. sphingolipids, sphingosine and sphingosine cerebrosides c. sphingosine cerebrosides d. sphingolipids

Answer 447

a. sphingosine Not sphingolipids because general. Ceramide - sphingosine + fatty acids; long chain fatty acid amide derivative of sphingosine Cerebroside - sphingosine + fatty acids + single sugar residue

Question 448

Compare the boiling points and densities of alkyl halide and alkane a. Both are lower for alkyl halide b. Both are higher for alkyl halide c. Higher density and lower boiling point for alkyl halide. d. Lower density and higher boiling point for alkyl halide.

Answer 448

b. Both are higher for alkyl halide Tip: compare from example molecules (e.g. chloroethane vs ethane) in Perry's

Question 449

Alkyl halide reacts with a hydroxide to form what compound? a. alcohol b. alkene c. alkyne d. alkane

Answer 449

a. alcohol

Question 450

What is the type of isomerism of cis-1,4-cyclohexanol and trans-1,2-cyclohexanol? a. constitutional isomer b. stereoisomer c. both of these d. none of these

Answer 450

a. constitutional isomer

Question 451

What is the chemical formula of caffeine?

Answer 451

C8H10N4O2 Perry's T2-2

Question 452

There are 4 beakers, one with CCl4, one with dry ice, one exposed to air, and one with water. Which will get heated inside a microwave oven? a. CCl b. dry ice c. air d. water

Answer 452

d. water Microwaves only heat up polar substances (those w/ dipole moments)

Question 453

Radioactive material B initially has 8 times the amount of radioactive material A. After three half-lives of A, both of them have the same amount. What can be said about the half-life of A as compared to B?

Answer 453

Half life of x is twice that of y Use ratio and proportion using half-life formula

Question 454

Hydrazine reacts with dinitrogen tetroxide to form nitrogen gas. How many kg of nitrogen gas can be formed from 200 kg of hydrazine? a. 131 b. 262 c. 29.1 d. 65.6

Answer 454

b. 262 Familiarize: 2N2H4 + N2O4 -> 3N2 + 4H2O

Question 455

The design flow and overflow rates for a settling tank are 0.044 m3 s-1 and 20 m day-1, respectively. If two tanks are used and the surface area is 190 m2, find the depth of each tank. The width of each tank is 12 m and the detention time is 2 hrs.

Answer 455

1.67 Use V = SA*h, to get h

Question 456

Given the equation as follows: dM/dt = d(in)/dt - d(out)/dt - kCV C(in) = 180 mg/L C(out) = 430 m3/d Decay coefficient = 0.70 d-1 Surface area = 10 ha Depth = 1.0 m Find the steady state concentration at the exit.

Answer 456

1.1 mg/L Typo: 430 m3/d is Vo, Find Cout Use v/vo = (Cao-Ca)/kCa

Question 457

Rank the strength of bonds of formic acid

Answer 457

C=O > C-H H-O > H-C

Question 458

Rank of toxicity of Cu, As, DDT, heptachlor and lindane in water

Answer 458

Copper < Lindane < DDT < Heptachlor < Arsenic

Question 459

What is the organic molecular formula for a certain organic polychlorinate biphenyl similar to chlorinated insecticides if the compound contains 3.95% carbon, 1.131% hydrogen, and 58.95% chlorine with a molecular mass of 360.89? a. C14H8Cl14 b. C6H2Cl13 c. C10H8Cl12 d. C12H6Cl16

Answer 459

d. C12H6Cl16 T 2-141: 8TH Ed

Question 460

Determine the organic molecular formula of melamine used in the process of manufacturing formica. It is composed of 28.57% carbon, 4.82% hydrogen and 66.634% nitrogen, and has a molecular mass of 126.122. a. (C2H2N2)4 b. (C3H3N3)3 c. C4H8N4 d. (CH2N2)3

Answer 460

d. (CH2N2)3 Compare molar mass or Check Perrys T2-154

Question 461

If the temperature at the beginning of the compression process of an air standard Otto cycle is 27°C at a compression ratio of 8, pressure at 101. 1kPa and cylinder volume of 566.2cm°, determine the: 1. The thermal efficiency 2. The mean effective pressure using the PG model for air. Maximum temperature during the cycle is 1727°C. 3. If the IG model was used, find the answers. a. 56.5%, 710.2kPa, 51%, 806kPa b. 43.2%, 620.5kPa, 61%, 906kPa c. 58.5%, 750.2kPa, 71%, 760kPa d. 65.8%, 810.8kPa, 81%, 660kPa

Answer 461

a. 56.5%, 710.2kPa, 51%, 806kPa Find isa na correct. Here, calculate for thermal efficiency. η=1-1/(r^𝛾-1)=1-1/(8^(1.4-1))=56.5%

Question 462

Assuming that air at sea level is composed of 20% oxygen and 80% nitrogen, determine the pressure and air composition on top of Mount Everest at 0°C and air altitude of 29143ft. a. 0.299bar, Y_O2=0.179, YN2=0.866 b. 0.333bar, Y_O2=0.177, YN2=0.823 c. 0.516bar, Y_O2=0.236, YN2=1.021 d. 0.411bar, Y_O2=0.187, YN2=0.911

Answer 462

b. 0.333bar, Y_O2=0.177, YN2=0.823 YO2 + YN2 should be 1. B satisfies this.

Question 463

Identify the organic compounds in the following equation: CH3CH(OH)CH2CHO → CHCH=CHO + H2O a. Butanol; cis/trans butanol b. Butanoic acid; Butanoic acid c. Carbonyl aldehyde; cis or trans isomer d. Butanol; butaldehyde

Answer 463

d. Butanol; butaldehyde

Question 464

Define gluconeogenesis. a. Positive ions are smaller and negative ions are smaller than their corresponding atoms b. Positive ions are larger and negative ions are larger than their corresponding atoms c. Positive ions are smaller and negative ions are larger than their corresponding atoms d. Positive ions are larger and negative ions are smaller than their corresponding atoms

Answer 464

c. Positive ions are smaller and negative ions are larger than their corresponding atoms

Question 465

Applying the Gibbs phase rule in the degrees of freedom, determine the number of degrees of freedom of: 1. Liquid water in equilibrium with its vapor 2. Liquid water in equilibrium with a mixture of water vapor and nitrogen 3. A liquid solution of alcohol in water in equilibrium with its vapor A. F=1; F=4; F=3 B. F=2; F=3; F=3 C. F=1; F=2; F=2 D. F=2; F=3; F=2

Answer 465

C. F=1; F=2; F=2 df = C - P + 2 1) 1-2+1 = 1 2) 2-2+2 = 2 3) 2-2+2 = 2

Question 466

Estimate the energy emitted per photon as well as the quantity of photons emitted per second from a 100W yellow light bulb with y=550m and a 1kW microwave source with y=cm emitting 1.99×10-23 J/photon and 5.03×1025photons/s. a. 3.6x10-19 J and 2.77×10^20 photons/s b. 2.62×10-18 J and 3.11×10^21photons/s c. 3.91x10-20 J and 4.22x10^19photons/s d. 4.11x10-20 J and 1.67×10^20photons/s

Answer 466

a. 3.6x10-19 J and 2.77×10^20 photons/s Multiplying it should be equal to 100W

Question 467

How many moles of beryllium would a 43.1 lb sample of pure aquamarine with formula Be3Al2(SiO3)6 contain? a. 3.2×10^3mol b. 4.53mol c. 1.1×10^2mol d. 5.38×10^3mol

Answer 467

c. 1.1×102mol

Question 468

In 1986, the nuclear reactor in Chernobyl had an accident and spewed radioactive nuclei that were carried by the winds for hundreds of miles. Today, among the child survivors of the event, the most common damage is thyroid cancer. Which radioactive nucleus do you expect to be responsible for these cancers?

Answer 468

I-131

Question 469

Perchloroethylene, which is a liquid at room temperature, is one of the most widely used solvents for commercial dry cleaning. It is sold for this purpose under several trade names, including Perclene. Does this molecule have polar bonds? Is it a polar molecule? Does it have a dipole?

Answer 469

Yes, no, none

Question 470

classify these as kinetic or potential energy (1) Water held by a dam (2) A speeding train (3) A book on its edge before falling (4) A falling book (5) electric current in a light bulb a. kinetic, kinetic, potential, kinetic, kinetic b. kinetic, kinetic, potential, kinetic, potential c. potential, kinetic, potential, kinetic, potential d. potential, kinetic, kinetic, potential, kinetic, kinetic

Answer 470

d. potential, kinetic, kinetic, potential, kinetic, kinetic

Question 471

what process combines rubber and sulfur at a high temperature? a. fulmination b. vulcanization c. fermentation d. distillation

Answer 471

b. vulcanization

Question 472

Predict which of these ionic compounds are soluble in water: (1) MgCl2 (2) CaCO3 (3) Na2SO4 (4) NH4NO3 (5) Pb(OH)2 a. soluble, soluble, soluble, soluble, soluble b. soluble, insoluble, soluble, soluble, insoluble c. soluble, insoluble, insoluble, soluble, insoluble d. soluble, insoluble, insoluble, soluble, insoluble

Answer 472

d. soluble, insoluble, insoluble, soluble, insoluble

Question 473

The only natural amino acid that has no chiral center is: a. Cysteine b. Tryptophan c. Proline d. Glycine

Answer 473

d. Glycine

Question 474

Calculate the entropy change if 350 g of water at 5°C is mixed with 500 g of water at 70°C. a. 3.33 eu b. 6.67 eu c. 5.05 eu d. 4.49 eu

Answer 474

d. 4.49 eu

Question 475

which of the following is the best definition of the chemical nature of soap? a. A soap is a very long molecule. b. A soap is a long chain carboxylic acid. c. A soap is an ester of glycerol and a long chain carboxylic acid. d. A soap is a salt of a long chain carboxylic acid.

Answer 475

d. A soap is a salt of a long chain carboxylic acid.

Question 476

Given: Dodecane (1) Is it soluble in water? (2) Is it soluble in hexane? (3) Is it combustible? (4) Ig it solid, liquid or gas at room temperature and atmospheric conditions? (5) Is it denser than water? a. no, yes, yes, liquid, less dense b. no, yes, yes, gas, denser c. no, yes, no, liquid, legs dense d. no, no, yes, gas, dense

Answer 476

a. no, yes, yes, liquid, less dense

Question 477

which of the following has a larger ionic nucleus? Na+ or Na? a. Both b. Na c. Na+ d. none of these

Answer 477

b. Na More positive charge draws electrons closer

Question 478

What compound is a ketone but it is not a carbohydrate but is useful commercially? a. ethyl alcohol b. aldehyde c. glucose d. acetone

Answer 478

d. acetone

Question 479

which Republic Act is the PRC Modernization Act of 2000? a. R.A. 8750 b. R.A. 7897 c. R.A. 8890 d. R.A. 8981

Answer 479

d. R.A. 8981

Question 480

You are presented with a Lewis dot structure of element X as X. To which two groups in the Periodic Table might this element belong?

Answer 480

Group 2A

Question 481

A radioactive isotope with an intensity (activity) of 100 mCi per vial is delivered to a hospital. The vial contains 10 mL of liquid. The instruction is to administer 2.5 mci intravenously. How many milliliters of the liquid should be administered? a. 0.66 ml c. 0.40 ml b. 0.18 ml d. 0.25 ml

Answer 481

d. 0.25 ml

Question 482

The solubility of aspartic acid in water is 0.500 g in 100 mL at 25°c. If we digsolve 0.251 g of aspartic acid in 50.0 mL of water at 50°c and let the solution cool to 25°c without stirring, shaking, or otherwise disturbing the solution, would the resulting solution be a saturated, unsaturated, or supersaturated solution? a. saturated c. supersaturated b. unsaturated d. cannot be determined

Answer 482

c. supersaturated

Question 483

A certain liguid has a viscosity of 0.0001 poise and a density of 3.2 g/ml. How long will it take for platinum ball with 2.5 mm radius to fall 1 cm through the liquid? The density of the platinum is 21.4 g/ml. a. 33.4 s b. 40.5 s c. 28.4 s d. 48.9 s

Answer 483

b. 40.5 g Use settling velocity here

Question 484

Water on heating from 1 to 4°c a. contracts b. has same volume c. expands d. may contract or expand

Answer 484

a. contracts

Question 485

This law explains why aerosol cans carry the warning "Do not incinerate" A. Charles Law B. Gay-Lussac Law C. BovIes Law D. Dalton's Law of Partial Pressure

Answer 485

B. Gay-Lussac Law

Question 486

The normal boiling point of a substance depends on both the mass of the molecule and the attractive forces between molecules. Arrange the compounds in each set in order of increasing boiling point: (1) HCl, (2) HBr and (3) HI. a. HI < HBr < HCl b. HCl < HI < HBr c. HCl < HBr < HI d. HI < HC1 < HBr

Answer 486

c. HCl < HBr < HI

Question 487

What is the specific gas constant of dry air in J/kg per unit Kelvin? a. 0.287 b. 28.7 c. 2.87 d. 287

Answer 487

d. 287

Question 488

Write an equation for the reaction of HCl with each compound. which are acid-base reactions? Which are redox reactions? (1) Na,co, (5) Fe,o, (2) Mg (6) CH2NH3 (3) NaOH (7) NaHCO3 (4) NH3 a. none b. (1), (2) and (7) c. only (2) d. only (6)

Answer 488

c. only (2)

Question 489

In an endothermic reaction, the activation energy is 10.0 kcal/mol. Is the activation energy of the reverse reaction also 10.0 kcal/mol, or would it be more or less? a. less b. the same c. more d. cannot be determined

Answer 489

b. the same

Question 490

_____ is. a rather disagreeable-smelling liquid used as a preservative for laboratory specimens. A. Acetaldehyde B. Methanol C. Methanal D. Valeraldehyde

Answer 490

C. Methanal

Question 491

Reaction proceeds sponataneously at low temperatures. At high temperatures, the reverse reaction becomes spontaneous. A. +ΔH and +ΔS B. -ΔH and -ΔS C. -ΔH and +ΔS D. +ΔH and -ΔS

Answer 491

B. -ΔH and -ΔS

Question 492

The influence of mixing of s and p orbitals; the greater the fraction of s character of the hybrid orbital, the more electronegative is the atom a. Hybridization b. Hybrid Orbitals c. Hybridization Effect d. Hybrid

Answer 492

a. Hybridization

Question 493

The discharge from the Renenutet sugar beet plant causes the DO at the critical point to fall to 4.0 mg/L. The Meskhenet Stream has a negligible BOD and the initial deficit after the river and wastewater have mixed is zero. what DO will result if the concentration of the waste (Lw) is reduced by 50%? Assume that the flows remain the same and that the saturation value of DO is 10.83 mg/L in both cases. a. 6.1 mg/L c. 8.9 mg/L b. 7.4 mg/L d. 9.3 mg/L

Answer 493

b. 7.4 mg/I

Question 494

What concentration of Al, (SO,), has the same ionic strength as 0.1 M NaCI? a. 1.7×10-2 M b. 3.3x10-2 m c. 2.5×10-3 M d. 6.7x10-3 M

Answer 494

d. 6.7x10-3 M

Question 494

A landfill that is 12 ha in area has a liner of thickness 0.9 m. Each year 1700 m3 of leachate is collected. The hydraulic conductivity of the liner is 3.9 × 10-10 m * s-1, what is the head of water above the liner? a. 2 m b. 3 m c. 1 m d. 4 m

Answer 494

c. 1 m

Question 495

Above the stratosphere, the concentration of ozone and other gases is low, and the temperature decreases with increasing altitude

Answer 495

mesosphere

Question 496

How many grams of urea must be added to 4000 grams of water to make the solution boil at 100.32°C? a. 75.3 grams b. 185.4 grams c. 150.5 grams d. 205.6 grams

Answer 496

c. 150.5 grams Use boiling point elevation urea is the solute for molality

Question 497

what is the solubility of CaF2; in water in mols of CaF2 per L of solution? Ksp for CaF2, is 1.7 × 10^-10. a. 9.2x10^-6 M b. 3.5×10^-4 M c. 1.3×10^-5 M d. 5.5×10^-4 M

Answer 497

b. 3.5×10^-4 M Ksp = 4s^3

Question 498

You work in a lab and it is known that radioactivity is being emitted with an intensity of 175 mci at a distance of 1.0 m from the source. How far, in meters, from the source should you stand if you wish to be subjected to no more than 0.20 mCi?

Answer 498

30 m I1//I2 = (R2/R1)^2

Question 499

Consider the system A (g) → B (g) at 25°C. Assuming GA° = 8996 J/mol and GB° = 11718 J/mol, calculate the value of equilibrium constant for this reaction. A. 1.98 B. 0.50 C. 2.56 D. 0.33

Answer 499

D. 0.33

Question 500

Calculate the ultimate BOD in ppm and k in /day. Time (days) BOD (mg/L) 2 10 4 16 6 20 A. 33 ppm, 0.15/d B. 20 ppm, 0.21/d C. 27 ppm, 0.23/d D. 35 pmm, 0.18/d

Answer 500

C. 27 ppm, 0.23/d Use BODt=Lo(1-e^-kt)

Question 501

If a wastewater has a soluble orthophosphate concentration of 4.00 mg · L −1 as P, what theoretical amount of ferric chloride will be required to remove it completely? A. 45 mg/L C. 21 mg/L B. 33 mg/L D. 17 mg/L

Answer 501

C. 21 mg/L

Question 502

Which of the following physical properties differ for each of a pair of enantiomers? A. Boiling point and melting point B. Direction of rotation of plane-polarized light C. Index of refraction D. Solubility in ethanol

Answer 502

B. Direction of rotation of plane-polarized light

Question 503

The free neutron is an unstable particle that decays into a proton. What other particle is formed in neutron decay, and what is the maximum kinetic energy (in MeV) that it can possess? A. alpha, 0.66 MeV B. gamma, 0.42 MeV C. positron, 0.50 MeV D. electron, 0.78 MeV

Answer 503

D. electron, 0.78 MeV

Question 504

Does oxidation and reduction go hand and hand?

Answer 504

YES, because it involves the transfer of electrons from the oxidizing one to the reducing one

Question 505

What are amino acids with sulfur-containing groups

Answer 505

Methionine, cysteine, homocysteine, and taurine

Question 506

Choose the common methods in the removal of fine particle in hot airstream in cement production. A. buoyancy B. cyclone separator C. ESP D. venturi scrubber

Answer 506

C. ESP