Nov 2019

Question 1

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 1

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

Question 2

If radon -222 disintegrates to a stable condition by emitting three alpha emission and two beta emission, determine the stable nucleus formed.a. 222Rn86b. 192Ir77c. 137Cs55d. 210Pb82
If radon -222 disintegrates to a stable condition by emitting three alpha emission and two beta emission, determine the stable nucleus formed.
a. 222Rn86
b. 192Ir77
c. 137Cs55
d. 210Pb82

Answer 2

210Pb82

Question 3

The person’s senses 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 type of organic compound associated with the sense of smell and taste. The chemical identified was;
A. an alcohol
B. rhodopsin
C. an ester
D. an isomer

Answer 3

rhodopsin

Question 4

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 4

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

Question 5

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 5

Radium and an alpha particle

Question 6

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 6

stearic acid and glycerol

Question 7

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

Answer 7

8

Question 8

In the collision theory of chemical kinetics, it is suggested that reaction rate is governed by the relationship rate= Pz exp (Ea/Rt). What can an enzyme do to the activation energy of the reaction -Ea?
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 or increasing the energy level of the reaction.

Answer 8

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

Question 9

A chemical reaction may occur;
A. When atoms of two elements undergo a loss in electrons for one element or a gain in electrons for the other;
B. When a nonmetal element steals electrons from another nonmetal element in order to achieve a stable configuration;
C. None of these
D. When covalent bonds in two elements are transformed into polar covalent bonding during an oxidation/ reduction process

Answer 9

When atoms of two elements undergo a loss in electrons for one element or a gain in electrons for the other

Question 10

To which subatomic particle does each statement refer to a) has a positive charge; b) is found outside of the nucleus; c) has the smallest mass; d) has a negative charge
A. electron, electron, proton, proton
B. proton, electron, proton, electron
C. electron, proton, electron, proton
D. proton, electron, electron, proton

Answer 10

proton, electron, proton, electron

Question 11

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 11

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

Question 12

Define a salt in terms of acid and bases.
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 atom 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 12

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

Question 13

In order to describe the intensive state of a system at equilibrium, specify the degrees of freedom for a one-phase, two phase system and three phase system:
A. F=2; F=l; and F=0
B. F=1; F=2; and F=3
C. F=0; F=1; and F=2
D. F=3; F=2; and F=1

Answer 13

F=2; F=l; and F=0

Question 14

Applying the Octet Rule, determine how many electrons each must each atom gain or lose 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 neon;
B. neon; argon and krypton; krypton;
C. none of these
D. argon; krypton; krypton and argon;

Answer 14

krypton; argon; argon and neon

Question 15

If a labeled fatty acid with radioactive Carbon -14 is fed to an experimental animal, in what type of compounds contained in the breath of the animal would the radioactive material appear?
A. as nitrogen
B. as CO2
C. as water vapor
D. as hydrogen
(numerade answer)

Answer 15

as CO2

Question 16

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

Answer 16

fullerene

Question 17

Determine whether the following statements are TRUE (T) or FALSE (F)
about constitutional isomers:
a. They have the same molecular formula
b. They have the same physical properties
c. They have the same molecular weight
d. They have the connectivity of their atoms
A. T, F, T, F
B. F, T, F, T
C. T, F, F, T
D. F, F, T, T

Answer 17

T, F, T, F

Question 18

The element neon was discovered in 1898 by;
A. Marks and Howell
B. Travers and Ramsey
C. Davy and Russel
D. Pontin and Berzelius

Answer 18

Travers and Ramsey

Question 19

A gaseous system contains CO, CO2, H2, H2O and C6H6 in chemical equilibrium. Determine how many components here are, how many independent reactions and number of degrees of freedom?

A. 1;2;4
B. none of these
C. 2;3; 6
D. 3;2;4
(chatgpt answer)

Answer 19

3;2;4

Question 20

Applying the Gibbs phase rule in the degrees of freedom, determine the number of degrees of freedom of a: liquid water in equilibrium with its vapour; b: liquid water in equilibrium with a mixture of water vapor and nitrogen; c: 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 20

F=1;F=2; F=2

Question 21

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 in a 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 oslid state, only the pure solid systems will separate cut on cooling solutions.
D. It postulates that if the temperature and pressure are both given by the equation.

Answer 21

It postulates that if the temperature and pressure are both given by the equation.

Question 22

Biochemical compounds are either hydrophilic, hydrophobic or ampiphatic.
Classify the following compounds; glucose, stearic acid, soaps, fatty acids.
A. Ampiphatic, ampihatic, hydrophobic, hydrophobic
B. Hydrophilic, hydrophobic, ampiphatic, hydrophobic
c: Hydrophilit, amp-pratic, ampiphatic, hydrophobic
D. Hydrophobic, hydrophilic, hydrophobic, ampiphatic

Answer 22

Hydrophilic, hydrophobic, ampiphatic, hydrophobic

Question 23

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

Answer 23

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

Question 24

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

Answer 24

Esters

Question 25

The two most common components of acid rain are; A. nitric and carbonic acid B. nitric acid and sulfuric acid C. carbonic acid and sulfuric acid D. phosphoric acid and nitric acid

Answer 25

nitric acid and sulfuric acid

Question 26

Are galvanic cells and electrolytic cells the same? Why? A.No, because galvanic cells are electrochemical cells in which chemical cells occur spontaneously; 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 sources 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 26

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

Question 27

State Le Chatelier's principle; A. Le Chateliers 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 chateliers principle are blowing your breath through a straw and dissolving alka seltzer tablet in a glass of water. D. Le Chateliers 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 27

All of these

Question 28

Define is DNA? RNA? A. Beta ribose phosphoric acid and 1,2 ribonucleic add B. Deoxyribo-nucleic acid and ribonusleic acid C. Di-oxyl nucleic acid and cystosine D. 1,2-deoxyribose and cystosine

Answer 28

Deoxyribo-nucleic acid and ribonusleic acid

Question 29

In a dehydration reaction where water is lost, an organic compound C3H8O reacts with concentrated phosphoric and a product is formed. This product rapidly decolorizes a solution of bromine in tetrachlormethane. What is a product? A. Propanol B. Propanolol-2 C. Propene D. Propanol-1

Answer 29

Propene

Question 30

Match the radioactive isotope with its proper use: a. Cobalt 60 b. Thallium 201 c.Tritium d. Mercury 197 1. heart scan in exercise 2. measure water content of body 3. kidney scan 4. cancer therapy A. a-2; b-3; c-4; d-1 B. a-1; b-2; c-3; d-4 C. a-3; b-4; c-1; d-2 D. a-4; b-1; c-2; d-3

Answer 30

a-4; b-1; c-2; d-3

Question 31

Name the major physiologically active substance that comes from: bark 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 resarpine D. Salicin, beta-endomorphin, opium, atropine

Answer 31

Salicin, beta-endomorphin, opium, atropine

Question 32

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

Answer 32

-COOH

Question 33

Define entropy. A. Entropy is a function of the state of the system and determines whether a physical change or chemical reaction can occur spontaneously 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 33

Entropy is a function of the state of the system and determines whether a physical change or chemical reaction can occur spontaneously in a closed system

Question 34

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 34

Linus Pauling

Question 35

When the same amount of solid iodine is added to two identical glass tubes, stoppered and then heated to the same temperature, it was observed that the color in the two tubes is seen to be the same and solid iodine is still present in the bottom of the tubes. If a lot of additional iodine crystals are added to one of the tubes, is(are) there any charge (s). A. there is no change in the color of the vapor. B. the iodine crystals are not dissolved. C. the color of the vapor in that tube will become lighter. D. the color of the vapor in that tube will become darker.

Answer 35

the color of the vapor in that tube will become darker

Question 36

If there are two closed systems with fixed volumes and in thermal contact, the changes in the properties of both systems may reach a certain state. If there systems are involved, then all systems are in equal state: A. True B. None of these C. False D. Not entirely true or false

Answer 36

True?

Question 37

Whatever the compound, the gram molecular weight contains the same number of molecules, known as Avogadro's number. It is expressed as A. 6.02 x 10^23 particles per mole B. 6.02 × 10^23 ions per mole C. 6.02 x 10^23 atoms per mole D. 6.02 x 10^23 electrons per mole

Answer 37

C. 6.02 x 10^23 atoms per mole

Question 38

The distance of the earth to the most remote normal galaxy is calculated to be : A. 2 x 10^22 meters B. 1.4 × 10^26 meters C. 4 x 10^16 meters D. 9 × 10^25 meters

Answer 38

D. 9 × 10^25 meters