CHEMISTRY FOR ENGINEERS

Question 1

Boyle’s Law is also known as ___

Answer 1

Mariotte’s Law

Question 2

Laughing gas formula

Answer 2

Nitrous oxide (N2O)

Question 3

Caustic soda formula

Answer 3

Sodium hydroxide (NaOH)

Question 4

Baking soda formula

Answer 4

Sodium bicarbonate (NaHCO3)

Question 5

the pressure that a gas will exert in a container assuming it was alone

Answer 5

partial pressure

Question 6

Monazite formula

Answer 6

PO4SiO4

Question 7

Nitroglycerin formula

Answer 7

C3H5N3O9

Question 8

Cleveite

Answer 8

UO2

Question 9

Chlorophyll formula

Answer 9

C55H72MgN4O5

Question 10

DNA formula

Answer 10

C39H50O22N15P3

Question 11

it denotes the relative amount of bonds H formed between the atoms of a molecule.

Answer 11

Empirical formula

Question 12

it denotes the actual number of each atom in a molecule

Answer 12

molecular formula

Question 13

[True or False]
Density usually decreases with increasing temperature

Answer 13

True

Question 14

the amount of heat necessary to raise the temperature of 1 g of liquid water by 1°C.

Answer 14

calorie

Question 15

The heart of the scientific method is the _____ by collecting facts.

Answer 15

testing of hypotheses and theories

Question 16

For medical purposes and to measure potential radiation damage, the absorbed dose is measured in ____. Different particles damage body tissues differently; the ___ is a measure of relative damage caused by type of radiation.

Answer 16

rads, rem

Question 17

_______ is the use of radionuclei for
diagnostic imaging and therapy.

Answer 17

Nuclear medicine

Question 18

______ is the combining of two lighter nuclei to form a heavier nucleus. The energy released in this process is the energy of our Sun.

Answer 18

Nuclear fusion

Question 19

_______ is the splitting of a heavier nucleus into two or more smaller nuclei.

Answer 19

Nuclear fission

Question 20

What kind of emission does not result in transmutation?

Answer 20

Gamma emission

Question 21

[True or False] Rates of nuclear reactions are not affected by temperature or catalysts.

Answer 21

True

Question 22

[True or False] Nuclear reactions release so much energy that the mass does change.

Answer 22

True

Question 23

[True or False] Elements typically do change in a nuclear reaction

Answer 23

True

Question 24

Isotope used for cancer therapy

Answer 24

Cobalt-60

Question 25

Isotope used for heart scanning and exercise stress tests

Answer 25

Thallium-201

Question 26

Isotope used to measure the water content in the body

Answer 26

Tritium

Question 27

Isotope used for kidney scanning

Answer 27

Mercury-197

Question 28

Isotope used for medical imaging and eye tumor diagnosis

Answer 28

Phosphorus-32

Question 29

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?

Answer 29

2 assumptions: (1) C-14 is continually generated in the upper atmosphere by the production and decay of N-14 (2) C-14 is incorporated into carbon dioxide and other carbon compounds are then distributed worldwide as part of the carbon cycle.

Question 30

Carbon-14 dating of the Shroud of Turin indicated that the plant from which the shroud was made was alive around AD 1350. To how many half-lives does this correspond?

Answer 30

a bit more than 10% of the half life of C-14

Question 31

Half life of C-14

Answer 31

5730 years

Question 32

One sievert is equal to ____ rem

Answer 32

100

Question 33

[True or False] an isotope is UNSTABLE if it has equal number of protons and neutrons

Answer 33

False

Question 34

The higher the neutron/proton ratio, the (lower,higher) is the half life of an isotope

Answer 34

Lower

Question 35

An unstable nucleus exhibits ______

Answer 35

radioactivity

Question 36

Protons and neutrons, the elementary particles that make up the nucleus, are called ______

Answer 36

Nucleons

Question 37

A _______ is a nucleus with a particular composition, that is, with specific numbers of the two types of nucleons.

Answer 37

Nuclide

Question 38

[True or False] Alpha particles are identical to helium-4 nuclei.

Answer 38

True

Question 39

____ particles are high speed electrons while ____ are very high energy photons

Answer 39

Beta, gamma rays

Question 40

The decaying, or reactant, nuclide is called the ______; the product nuclide is called the ______.

Answer 40

Parent, daughter

Question 41

The technique of radiocarbon dating, for which the American chemist __________ won the Nobel Prize in chemistry in 1960, is based on measuring the amounts of 14C and 12C in materials of biological origin.

Answer 41

Willard F. Libby

Question 42

nuclei of the stable hydrogen isotope deuterium, 2H

Answer 42

deuterons

Question 43

The world’s most powerful accelerator is the ________ near Geneva, Switzerland

Answer 43

Large Hadron Collider (LHC)

Question 44

The ______ invented by ______ in 1930, applies the principle of the linear accelerator but uses electromagnets to give the particle a spiral path to save space.

Answer 44

cyclotron, E. O. Lawrence

Question 45

The _______ uses a synchronously increasing magnetic field to make the particle’s path circular rather than spiral.

Answer 45

synchrotron

Question 46

[True or False] penetrating power is inversely related to the mass, charge, and energy of the emission

Answer 46

True

Question 47

[True or False] Alpha particles are massive and highly charged, which means that they interact with matter most strongly of the three common emissions.

Answer 47

True

Question 48

[True or False] an external gamma ray source is the most dangerous because the energy can ionize many layers of living tissue.

Answer 48

True

Question 49

A tiny amount of a radioisotope mixed with a large amount of a stable isotope of the same element can act as a ______, a chemical “beacon” emitting radiation that signals the presence of the substance.

Answer 49

Tracer

Question 50

the energy required to break 1 mol of nuclei into individual nucleons

Answer 50

Nuclear binding energy

Question 51

[True or False] the greater the binding energy per nucleon, the more stable the nuclide is.

Answer 51

True

Question 52

He pointed out that the lack of chemical reactivity of the noble gases (Group 8A) indicates a high degree of stability of their electron configuration

Answer 52

Gilbert N. Lewis

Question 53

a measure of an atom’s attraction for the electrons it shares in a chemical bond with another atom.

Answer 53

Electronegativity

Question 54

the most electronegative element

Answer 54

Fluorine

Question 55

The most widely used scale of electronegativities was devised by ________ in the 1930s. On the scale, fluorine, the most electronegative element, is assigned an electronegativity of 4.0, and all other elements are assigned values relative to fluorine.

Answer 55

Linus Pauling

Question 56

_____ measures the amount of energy necessary to remove an electron from an atom

Answer 56

Ionization energy

Question 57

_______ measures how tightly an atom holds the electrons that it shares with another atom

Answer 57

Electronegativity

Question 58

Who proposed the theory of resonance?

Answer 58

Linus Pauling

Question 59

According to this theory, many molecules and ions are best described by writing two or more Lewis structures and considering the real molecule or ion to be a hybrid of these structures.

Answer 59

Theory of resonance

Question 60

According to this model, the valence electrons of an atom may be involved in the formation of single, double, or triple bonds, or they may be unshared. Each combination creates a negatively charged region of electron density around the nucleus. Because like charges repel each other, the vari- ous regions of electron density around an atom spread out so that each is as far away as possible from the others.

Answer 60

valence-shell electron-pair repulsion (VSEPR) model.

Question 61

The ______ states that elements of Groups 1A–7A tend to gain or lose electrons so as to achieve an outer shell containing eight valence electrons.

Answer 61

Octet rule

Question 62

What are the three main inorganic components of one dry mixture currently used to create synthetic bone?

Answer 62

calcium dihydrogen phosphate, calcium phosphate, and calcium carbonate

Question 63

What is the medical use of barium sulfate

Answer 63

to visualize the gastrointestinal tract by x-ray examination.

Question 64

What is the main metal ion present in bone and tooth enamel?

Answer 64

Ca2+

Question 65

If you read the labels of sun-blocking lotions, you will find that a common UV-blocking agent is a compound containing zinc. Name and write the formula of this zinc-containing compound.

Answer 65

Zinc Oxide

Question 66

We are constantly warned about the dangers of “lead- based” paints. Name and write the formula for a lead- containing compound found in lead-based paints.

Answer 66

Lead(IV) oxide and lead(IV) carbonate

Question 67

Iron forms Fe2+ and Fe3+ ions. Which ion is found in the over-the-counter preparations intended to treat “iron-poor blood”?

Answer 67

Fe2+

Question 68

Teflon

Answer 68

Tetrafluoroethylene

Question 69

[True or False] The amount of heat given off or absorbed is proportional to the amount of material.

Answer 69

True

Question 70

Major component of natural gas

Answer 70

Methane

Question 71

Major component of LPG or bottled gas

Answer 71

Propane

Question 72

Which of 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 72

D. Polyethylene fiber

Question 73

Used by Kevlar (bulletproof vest) A. Polymethacrylate fiber B. Polyamide fiber C. Polycarbonate fiber D. Polyethylene fiber

Answer 73

B. Polyamide fiber

Question 74

Which of the following polymers is a common material of construction for radiation protection A. Polymethacrylate fiber B. Polyamide fiber C. Polycarbonate fiber D. Polyethylene fiber

Answer 74

A. Polymethacrylate fiber

Question 75

Which of the following polymers used for bulletproof windows? A. Polymethacrylate fiber B. Polyamide fiber C. Polycarbonate fiber D. Polyethylene fiber

Answer 75

C. Polycarbonate fiber

Question 76

Commonly used in identifying the molecular mass (actual MW) of a compound

Answer 76

Platinichloride Method

Question 77

“Electron” was coined by _____

Answer 77

George Storey

Question 78

He did the oil drop experiment and determined the charge of an electron

Answer 78

Robert Millikan

Question 79

He proposed that energy like matter is discontinuous

Answer 79

Max Planck

Question 80

According to ____, a system may possess an infinite amount of energy.

Answer 80

Classical Physics

Question 81

According to this theory, a system may only possess a finite, discrete amount of energy

Answer 81

Quantum Theory

Question 82

The cumulative energy that each particle of a system possesses

Answer 82

Internal Energy

Question 83

Van der Waal’s Force is also known as A. Dispersion force B. London force C. Instantaneous induced dipole interaction D. All of the above

Answer 83

D. All of the above

Question 84

Bonds between atoms

Answer 84

Intramolecular forces

Question 85

Bond between molecules

Answer 85

Intermolecular forces

Question 86

It occurs on the molecules on the surface of a liquid due to the unbalanced distribution of forces

Answer 86

Surface Tension

Question 87

He introduced the concept of entropy

Answer 87

Rudolf Clausius

Question 88

A thermodynamic property that measures the various ways in which a systems energy can be dstributed among its components

Answer 88

Entropy

Question 89

Proponent of wave-particle duality

Answer 89

Albert Einstein

Question 90

The process is _____ when the entropy of the universe is positive while the gibbs free energy of the system is negative A) Spontaneous B) Non spontaneous C) Reversible, equilibrium

Answer 90

A) Spontaneous

Question 91

The process is _____ when the entropy of the universe is negative while the gibbs free energy of the system is positive A) Spontaneous B) Non spontaneous C) Reversible, equilibrium

Answer 91

B

Question 92

The process is _____ when the entropy of the universe and the gibbs free energy of the system are zero A) Spontaneous B) Non spontaneous C) Reversible, equilibrium

Answer 92

C

Question 93

The process involves the addition of infinitesimal amounts of heat to a system that causes incremental changes in its properties

Answer 93

Reversible

Question 94

Liquid to vapor phase transition involves ____ enthalpy and ____ entropy A) positive, negative B) negative, negative C) positive, positive D) negative, positive

Answer 94

C

Question 95

It is a measure for the maximum available energy for non-PV work

Answer 95

Gibb’s Free Energy

Question 96

[True or False] Colligative properties depend ONLY on the concentration of the solute

Answer 96

True

Question 97

The amount of pressure necessary to impede the phenomena of osmosis

Answer 97

Osmotic pressure

Question 98

A phenomena of solvent to flow through a semipermeable membrane to equalize the concentration on both sides

Answer 98

Osmosis

Question 99

He discovered the noble gases

Answer 99

William Ramsey

Question 100

Which of the ff is the third gas that William Ramsay isolated with Morris Travers A) Argon B) Neon C) Krypton D) Xenon

Answer 100

D) Xenon

Question 101

The gas that William Ramsay discovered along with Lord Rayleigh

Answer 101

Argon

Question 102

The gas that William Ramsay discovered along with Frederick Soddy

Answer 102

Radon “Radium Emanation”

Question 103

Three gases that Ramsay and Travers discovered

Answer 103

Neon, Krypton, Xenon

Question 104

A noble gas derived from an ire of uranium (cleveite)

Answer 104

Helium

Question 105

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

Answer 105

C60

Question 106

Who discovered radioactivity?

Answer 106

Henri Becquerel

Question 107

Marie Curie discovered these two elements

Answer 107

Polonium and Radium

Question 108

Father of nuclear chemistry

Answer 108

Otto Hahn

Question 109

Discovered nuclear fission

Answer 109

Otto Hahn

Question 110

Discovered transmutation (the nuclei of an atom will undergo transformation when bombarded w/ a nuclear species

Answer 110

Ernest Rutherford

Question 111

Who synthesized the first synthetic transmutated atom

Answer 111

Irene Joliot Curie

Question 112

First transmutated atom

Answer 112

P-30

Question 113

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 113

C: A Geiger Counter containing Argon and Boron trifluoride

Question 114

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 114

C: NaI Crystals containing Thallium (II) Iodide

Question 115

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 115

D: 100 rad Alpha Emission

Question 116

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 116

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

Question 117

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 117

C: Loss of proper cooling and/or moderator

Question 118

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 118

C: 8.0 mm of Lucite

Question 119

Quantum number - distance of e- from nucleus

Answer 119

n (principal quantum number)

Question 120

Quantum number - shape of the volume of space that the e- occupies

Answer 120

l azimuthal/angular momentum

Question 121

Quantum number - orientation of orbital in space

Answer 121

ml magnetic

Question 122

Quantum number - interaction with a magnetic field

Answer 122

ms spin

Question 123

Same number of electrons / same number of electronic configuration A) isoelectronic B) isotone C) isotope D) isobar

Answer 123

A

Question 124

Same number of neutrons A) isoelectronic B) isotone C) isotope D) isobar

Answer 124

B

Question 125

Same number of protons but different mass number A) isoelectronic B) isotone C) isotope D) isobar

Answer 125

C

Question 126

Same mass number A) isoelectronic B) isotone C) isotope D) isobar

Answer 126

D

Question 127

the ___ principle means fill the orbitals from bottom to top.

Answer 127

Aufbau

Question 128

_____ rule requires single occupancy before pairing.

Answer 128

Hund's

Question 129

No two electrons in a atom can have an identical set of four quantum numbers

Answer 129

Pauli's Exclusion Principle

Question 130

Who proposed Quantum Theory?

Answer 130

Max Planck

Question 131

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

Answer 131

B: 3

Question 132

What intermolecular forces does CH3CHOHCH3 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 132

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

Question 133

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

Answer 133

B:CH3OH

Question 134

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 134

D: True, False, True, False

Question 135

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 135

B: False, False, True

Question 136

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

Answer 136

C: delta S_universe > 0

Question 137

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 137

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

Question 138

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 138

D: Chlorine Atoms

Question 139

For a biochemical study involving the tigers at Malabon Zoo, a fatty acid was labeled with carbon-14. The sample was then fed to the tigers and after a few hours the tigers breath was analyzed. In which among the following compounds would you expect for the radioactive material to be detected? A: As Nitrogen B: As Carbon Dioxide C: As Hydrogen D: As Water Vapor

Answer 139

B: As Carbon Dioxide

Question 140

Raschig process is the production of ____

Answer 140

hydrazine

Question 141

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

Answer 141

A: 17.3%

Question 142

give the balanced chemical equation of Raschig process

Answer 142

2NH3 + Cl2 + 2NaOH --> N2H4 + 2NaCl + H2O

Question 143

Which among the following radioactive nuclide is often bombarded with the various isotopes of lead in order to produce most of the new superheavy elements? A: Iodine-131 and Lawrencium-257 B: Chromium-51 and Gallium-67 C: Calcium-48 and Nickel-64 D: Selenium-75 and Krypton-81m

Answer 143

C: Calcium-48 and Nickel-64

Question 144

who discovered superheavy elements from Plutonium to Lawrencium

Answer 144

Glenn T. Seaborg

Question 145

who discovered I-131

Answer 145

Glenn T. Seaborg

Question 146

Isotope to diagnose albinism

Answer 146

Cr-51

Question 147

Isotope for whole body scan for tumors

Answer 147

Gallium-67

Question 148

Buck and Axel

Answer 148

Olfactory receptors

Question 149

Vitamin A

Answer 149

Retinol

Question 150

Vitamin B12

Answer 150

Cobalamin

Question 151

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

Answer 151

D. 2

Question 152

What is another name for lecithin? A. Phosphatidylcholine C. Sodium benzoate B. Xanthan gum D. Ascorbic acid

Answer 152

A. Phosphatidylcholine

Question 153

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 153

D. They are both hydroxy acids

Question 154

Define a salt in terms of acids and bases. A. A salt is a compound that follows Le Chatelier principle in reactions with other compounds. B. All of these C. A salt is a compound formed when the nucleus of a hydrogen atom enters a quantity of water. D. A salt is a compound (other than water) produced by the reaction of acid and a base.

Answer 154

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

Question 155

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 155

A. Must always increase

Question 156

For a particular chemical reaction, ΔH˚ is positive and ΔS˚ is negative. Which of the following statements about the spontaneity of the reaction under standard conditions is TRUE? A. The reaction will be spontaneous only if the magnitude of ΔH˚ is large enough to cover the unfavorable entropy change. B. The reaction will be spontaneous only if the magnitude of ΔS˚ is large enough to overcome the unfavorable enthalpy change. C. The reaction will be spontaneous regardless of the magnitudes of ΔH˚ and ΔS˚. D. The reaction cannot be spontaneous.

Answer 156

D. The reaction cannot be spontaneous.

Question 157

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

Answer 157

D. underground burial in concrete containers

Question 158

Which forces are stronger, intramolecular covalent bonds or intermolecular hydrogen bonds?

Answer 158

Intramolecular covalent bonds are stronger than intermolecular hydrogen bonds.

Question 159

Which types of solids have the highest melting points? Which have the lowest melting points?

Answer 159

Ionic and network solids have the highest melting points. Molecular solids have the lowest melting points.

Question 160

What happens when a person lowers the diaphragm in his or her chest cavity?

Answer 160

When the diaphragm is lowered, the volume of the chest cavity increases, lowering the pressure in the lungs relative to the atmospheric pressure. Air at atmospheric pressure then rushes into the lungs, beginning the breathing process.

Question 161

In a sphygmomanometer one listens to the first tapping sound as the constrictive pressure of the arm cuff is slowly released. What is the significance of this tapping sound?

Answer 161

The first tapping sound one hears is the systolic pressure, which occurs when the sphygmomanometer pressure matches the blood pressure when the ventricle contracts, pushing blood into the arm.

Question 162

If you fill a glass bottle with water, cap it, and cool to 210°C, the bottle will crack. Explain.

Answer 162

When water freezes, it expands (water is one of the few substances that expands on freezing) and will crack the bottle when the ice expansion exceeds the volume of the bottle. 6.83 It is difficult to compress liquids and solids because their molecules are already very close together and there is very little empty space between them

Question 163

Why do aerosol cans carry the warning “Do not incinerate”?

Answer 163

Aerosol cans already contain gases under high pressure. Gay-Lussac’s law predicts that the pressure inside the can will increase with increasing temperature, with the potential of explosive rupture of the can, causing injury.

Question 164

Why does the temperature of a liquid drop as a result of evaporation?

Answer 164

The temperature of a liquid decreases during evaporation because the molecules with higher kinetic energy leave the liquid, which decreases the average kinetic energy of those molecules remaining in the liquid.

Question 165

To a separatory funnel with two layers—the nonpolar diethyl ether and the polar water—is added a small amount of solid. After shaking the separatory funnel, in which layer will we find each of the following solids? (a) NaCl (b) Camphor, C10H16O (c) KOH

Answer 165

(a) NaCl (an ionic solid) will dissolve in the polar water layer. (b) Camphor (a nonpolar molecule) will dissolve in the nonpolar diethyl ether layer. (c) KOH (an ionic solid) will dissolve in the polar water layer.

Question 166

Suppose that we have a stain on an oil painting that we want to remove without damaging the painting. The stain is not water-insoluble. Knowing the polarities of the following solvents, which one would we try first and why? (a) Benzene, C6H6 (b) Isopropyl (rubbing) alcohol, C3H7OH (c) Hexane, C6H14

Answer 166

Isopropyl alcohol would be a good first choice. The oil base in the paint is nonpolar. Both benzene and hexane are nonpolar solvents and may dissolve the paint, destroying the painting

Question 167

The solubility of aspartic acid in water is 0.500 g in 100 mL at 25°C. If we dissolve 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? Explain.

Answer 167

supersaturated

Question 168

If a bottle of beer is allowed to stand for several hours after being opened, it becomes “flat” (it loses CO2). Explain.

Answer 168

According to Henry’s law, the solubility of a gas in a liquid is directly proportional to the pressure. A closed bottle of a carbonated beverage is under excess CO2 pressure. After the bottle is opened, the excess CO2 pressure is released and the CO2 escapes from solution as bubbles of gas.

Question 169

Which of the following would produce the brightest light in the conductance apparatus shown in Figure 7.10? (a) 0.1 M KCl (b) 0.1 M (NH4)3PO4 (c) 0.5 M sucrose

Answer 169

(b) 0.1 M (NH4)3PO

Question 170

On the basis of Tables 7.1 and 7.2, classify the following systems as homogeneous, heterogeneous, or colloidal mixtures. (a) Physiological saline solution (b) Orange juice (c) A cloud (d) Wet sand (e) Suds (f ) Milk

Answer 170

(a) homogeneous (b) heterogeneous (c) colloidal (d) heterogeneous (e) colloidal (f) colloidal

Question 171

A solution of protein is transparent at room temperature. When it is cooled to10°C, it becomes turbid. What causes this change in appearance?

Answer 171

As the temperature of the solution decreases, the protein molecules aggregate and form a colloidal mixture. The turbid appearance is the result of the Tyndall effect.

Question 172

What makes normal rainwater slightly acidic?

Answer 172

Carbon dioxide (CO2) dissolves in rainwater to form a dilute solution of carbonic acid (H2CO3), which is a weak acid

Question 173

What is nitrogen narcosis?

Answer 173

Nitrogen dissolved in the blood can lead to a narcotic effect referred to as “rapture of the deep,” which is similar to alcohol-induced intoxication.

Question 174

What is the chemical formula for the main component of limestone and marble?

Answer 174

calcium carbonate, CaCO3.

Question 175

What is the minimum pressure on sea water that will force water to flow from the concentrated solution into the dilute solution?

Answer 175

The minimum pressure required for reverse osmosis in the desalinization of sea water exceeds 100 atm (the osmotic pressure of sea water).

Question 176

What is the minimum pressure on sea water that will force water to flow from the concentrated solution into the dilute solution?

Answer 176

The minimum pressure required for reverse osmosis in the desalinization of sea water exceeds 100 atm (the osmotic pressure of sea water).

Question 177

Synovial fluid that exists in joints is a colloidal solution of hyaluronic acid (Section 20.6A) in water. When a biochemist wants to isolate hyaluronic acid from synovial fluid, he or she adds ethanol, C2H6O, to bring the solution to 65% ethanol. The hyaluronic acid precipitates upon standing. What makes the hyaluronic acid solution unstable and causes it to precipitate?

Answer 177

The ethanol molecules

Question 178

If a certain reaction takes 16 h to go to completion at 10°C, what temperature should we run it if we want it to go to completion in 1 h?

Answer 178

50°C would predict completion of the reaction in 1 h

Question 179

If you were running a reaction and wanted it to go faster, what three things might you try to accomplish this goal?

Answer 179

You might (a) increase the temperature, (b) increase the concentration of reactants, or (c) add a catalyst.

Question 180

Explain how a catalyst increases the rate of a reaction

Answer 180

A catalyst increases the rate of a reaction by providing an alternative reaction pathway with lower activation energy.

Question 181

A painkiller—for example, Tylenol—can be purchased in two forms, each containing the same amount of drug. One form is a solid coated pill, and the other is a capsule that contains tiny beads and has the same coat. Which medication will act faster? Explain

Answer 181

The capsule with the tiny beads will act faster than the solid coated-pill form. The small bead size increases the drug’s surface area, allowing the drug to react faster and deliver its therapeutic effects more quickly.

Question 182

Which weak base is used as a flame retardant in plastics?

Answer 182

Mg(OH)2 is a weak base used in flame-retardant plastics.

Question 183

With respect to corneal burns, are strong acids or strong bases more dangerous?

Answer 183

Strong bases are more harmful to the cornea because the healing of the wounds can deposit nontransparent scar tissue that impairs vision

Question 184

What causes (a) respiratory acidosis and (b) metabolic acidosis?

Answer 184

(a) Respiratory acidosis is caused by hypoventilation, which occurs due to a variety of breathing difficulties, such as a windpipe obstruction, asthma, or pneumonia. (b) Metabolic acidosis is caused by starvation or heavy exercise

Question 185

Suppose you have a phosphate buffer of pH 7.21. If you add more solid NaH2PO4 to this buffer, would you expect the pH of the buffer to increase, decrease, or remain unchanged? Explain

Answer 185

DECREASE As the concentration of H2PO4 increases, the log becomes negative, lowering the pH and becoming more acidic.

Question 186

What is the ratio of HPO /H2PO in a phosphate buffer of pH 7.9 (the pH of human pancreatic fluid)?

Answer 186

4.9 : 1 or 5:1

Question 187

Name the major physiologically active substances that comes from: bark of the willow tree the pituitary gland, the sap of the poppy, belladenna plant.

Answer 187

Salicin, beta-endomorphin, opium, atropine

Question 188

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

Answer 188

C. A fullerene

Question 189

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

Answer 189

a. Sr2+

Question 190

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

Answer 190

d. yellow

Question 191

Substances whose solutions change color due to changes in pH

Answer 191

Indicator

Question 192

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

Answer 192

Appel Reaction

Question 193

Which of the following indicators is used in EDTA titration? A. Solochrome C. Eriochrome Black T B. Calmagite D. All of these

Answer 193

D. All of these

Question 194

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

Answer 194

A. –SO2OH

Question 195

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 195

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

Question 196

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 196

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 197

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 197

D. Where two equal masses undergo a glancing elastic collision

Question 198

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 198

C. All of it transferred to the road and surroundings

Question 199

Are reversible processes frictionless? Why? A. Because the processes are driven by forces which imbalance is differential in magnitude B. Because when reversed, retraces its forward path and restores the initial state of the system and surroundings C. None of these D. Because only infinitesimal changes occur

Answer 199

B. Because when reversed, retraces its forward path and restores the initial state of the system and surroundings

Question 200

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 200

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