Chapter 8

Question 1

In an exergonic process, the system

a. gains energy
b. loses energy
c. neither gains nor loses energy
d. more than one response is correct

Answer 1

b. loses energy

Question 2

At 20°C, a sample of solid spontaneously sublimes to a gas. This change in state is accompanied by which of the following changes in the solid sample?

a. entropy & energy decrease
b. entropy & energy increase
c. entropy decreases & energy increases
d. energy decreases & entropy increases

Answer 2

b. entropy & energy increase

Question 3

Which of the following states of matter generally has the lowest entropy?

a. a crystalline solid
b. a liquid
c. a gas
d. two of the three have virtually the same entropy

Answer 3

a. a crystalline solid

Question 4

The reaction conditions for a specific reaction, BCD + HA ⇔ ABCDH, are correct, but the reaction does not occur. What could be the reason?

a. There are no collisions between the molecules.
b. The collisions of the particles with the container walls removes the required energy because it is transferred to the container molecules.
c. The orientation of the molecules with respect to each other is not correct for the reaction to occur.
d. There is more than one answer.

Answer 4

c. the orientation of the molecules with respect to each other is not correct for the reaction to occur.

Question 5

Which is an incorrect statement when discussing molecular collisions leading to the chemical reaction,
AB + CD → AD + CB?
a. The faster the motion of the molecules, the more likely they are to collide.
b. The faster the motion of the molecules, the greater the probability that a chemical reaction will occur.
c. The slower the motion of the molecules, the more likely that this reaction will become an equilibrium reaction favoring the left side of the equation.
d. The relationship between molecular collisions and reaction rate is direct.

Answer 5

c. The slower the motion of the molecules, the more likely that this reaction will become an equilibrium reaction favoring the left side of the equation.

Question 6

Which of the following is most closely related to the term “reaction rate”?

a. the temperature needed to initiate a reaction
b. the position of equilibrium when a reaction stops
c. the speed of a reaction
d. more than one response is correct

Answer 6

c. the speed of a reaction

Question 7

Which of the following is an endergonic process?

a. exothermic reactions
b. endothermic reactions
c. equilibrium reactions
d. proposed reactions that do not proceed

Answer 7

b. endothermic reactions

Question 8

Which is assumed to be true in most explanations of how reactions occur?

a. reactant particles must collide with each other
b. catalysts must be present
c. energy must be absorbed as the reaction proceeds
d. more than one response is correct

Answer 8

a. reactant particles must collide with each other

Question 9

Which of the following will influence all reaction rates?

a. the presence of catalysts
b. the temperature of reactants
c. the concentration of reactants
d. more than one response is correct

Answer 9

d. more than one response is correct

Question 10

Homogeneous catalysts are thought to function by

a. raising the temperature
b. lowering activation energy of a reaction
c. removing a reacting molecule
d. more than one response is correct

Answer 10

b. lowering activation energy of a reaction

Question 11

If the reaction A + B C occurs and pure A and B were mixed, which of the following would take place as equilibrium was established?

a. The concentration of C would increase for a time, then remain constant.
b. The concentration of A would increase for a time, then decrease.
c. The concentration of B would increase for a time, then remain constant.
d. More than one response is correct.

Answer 11

a. the concentration of C would increase for a time, then remain constant

Question 12

In a system of equilibrium, it is true that

a. the rate of the forward reaction exceeds that of the reverse
b. the rate of the forward reaction is lower than that of the reverse reaction
c. the rate of the forward reaction is equal to the rate of the reverse reaction
d. more than one response is correct.

Answer 12

c. the rate of the forward reaction is equal to the rate of the reverse reaction

Question 13

Equilibrium:
The following question(s) refer to the following equilibrium in which all reactants and products are gases:
CH4 + H2O CH3OH + H2 + heat

Indicate the effect of the changing condition on the position of equilibrium.

Refer to Equilibrium. Add a catalyst to the mixture.

a. shifts left
b. shifts right
c. no effect
d. can shift to right or left

Answer 13

c. no effect

Question 14

BrCl is put into a 1.00 liter container. At equilibrium, the molar concentration of BrCl is 0.382, and that of Br2 is 0.319. Evaluate the equilibrium constant for the following reaction:
     Br2 + Cl2  2 BrCl (all are gases).
a.  0.457 
b.  0.699 
c.  1.43 
d.  5.74

Answer 14

c. 1.43

Question 15

When the equilibrium constant expression is written for the reaction N2 + 3F2 → 2NF3, what is the exponent of the concentration of fluorine, F2?

a. 1
b. 2
c. 3
d. 0

Answer 15

c. 3

Question 16

Which of the following statements about a K of 3.5 calculated for a specific chemical reaction at equilibrium is incorrect?

a. It was calculated by dividing the product of the products by that of the reactants.
b. It indicates that one side of the reaction has most of the matter present.
c. It is an evaluation of the extent of the two chemical reactions involved: the forward and the reverse reactions.
d. A K of 3.5 indicates that a catalyst will push the reaction to the right.

Answer 16

d. A K of 3.5 indicates that a catalyst will push the reaction to the right.

Question 17

Which method can be used to product a timed-release medication?

a. The patient is given the medication in small doses over time, rather than one larger dose.
b. The patient is to take the medication two or three times a day.
c. The medication is provided in special capsules that are subdivided into smaller, pulverized portions of the medicinal compound.
d. The medication compound is produced in very small amounts and each is coated with a material of varying thickness.

Answer 17

d. The medication compound is produced in very small amounts and each is coated with a material of varying thickness.

Question 18

Which of the statements is correct when referring to the equation?
H2(g) + I2(g) ⇔ 2HI(g)
a. This reaction is reversible because the amount of heat given off by the forward reaction is the same as the heat given off by the reverse reaction.
b. The state of the reaction is found by using the formula .
c. Most of the matter is on the right side of the equation.
d. There isn’t a correct response provided.

Answer 18

d. there isn’t a correct response provided

Question 19

CFC’s such as CF2Cl2, are associated with the increase in chemical activity that degrades ozone. Which of the following relates to this phenomenon?

a. This is not serious because the only area of the planet involved is at the poles and there is very little life to be affected by the increase in UV.
b. The catalyzing of the ozone breakdown decreases the amount of UV at the surface of the planet.
c. The process by which the ozone is degraded is catalytic and can be controlled by the reduction of CFC’s.
d. All of these responses are correct.

Answer 19

c. The process by which the ozone is degraded is catalytic and can be controlled by the reduction of CFC’s.

Question 20

An inhibitor will have what effect on a reaction?

a. increase the activation energy
b. lower the activation energy
c. slow the reaction down
d. lower the amount of product produced

Answer 20

c. slow the reaction down

Question 21

If we remove CO2 from the following equation, CO + H2O + heat CO2 + H2, which way will the equilibrium shift?

a. to the left
b. will have no effect
c. to the right
d. not enough information to know

Answer 21

c. to the right

Question 22

If we add a catalyst to the following equation, CO + H2O + heat CO2 + H2, which way will the equilibrium shift?

a. to the left
b. will have no effect
c. to the right
d. not enough information to know

Answer 22

b. will have no effect

Question 23

A process that gains or accepts energy as it takes place is a(n)

a. exergonic process
b. spontaneous process
c. endergonic process
d. all of these

Answer 23

c. endergonic process

Question 24

Ice has a(n) ____ entropy than that of liquid water.

a. lower
b. equal
c. higher
d. can not tell

Answer 24

a. lower

Question 25

The device used to measure heat produced or used by a chemical reaction is called a(n):

a. thermometer
b. calorimeter
c. activator
d. Joulery

Answer 25

b. calorimeter