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chemCh19review
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Another name for the activated complex is ____.
a. energy barrier
c. rate limiter
b. transition state
d. collision group
____
2. Why does a higher temperature cause a reaction to go faster?
a. There are more collisions per second only.
b. Collisions occur with greater energy only.
c. There are more collisions per second and the collisions are of greater energy.
d. There are more collisions per second or the collisions are of greater energy.
____
3. What happens to a catalyst in a reaction?
a. It is unchanged.
b. It is incorporated into the products.
c. It is incorporated into the reactants.
d. It evaporates away.
____
4. Which of the following substances act as catalysts in the body?
a. carbohydrates
c. lipids
b. nucleic acids
d. enzymes
____
5. If a reaction is reversible, what are the relative amounts of reactant and product at the end of the reaction?
a. no reactant; all product
b. no product; all reactant
c. some product; some reactant
d. The relationship between reactants and products cannot be determined.
____
6. What is the equilibrium constant for the following reaction?
C+O
CO
a.
c.
b.
d.
____
7. In an equilibrium reaction with a K
a. reactants are favored
b. reaction is spontaneous
of 1
10 , the ____.
c. the products are favored
d. reaction is exothermic
____
8. The energy that is available to do work in a reaction is called ____.
a. heat
c. entropy
b. enthalpy
d. free energy
____
9. Which physical state of nitrogen has the highest entropy?
a. solid
c. gas
b. liquid
d. vapor
____ 10. Which one of the following systems has the highest entropy?
a.
b.
c.
d.
10 mL of water at 10 C
10 mL of water at 50 C
10 mL of water at 100 C
All have the same entropy because all are water.
____ 11. In which of these systems is the entropy decreasing?
a. air escaping from a tire
c. salt dissolving in water
b. snow melting
d. a liquid cooling
____ 12. Which of the following statements is true?
a. All spontaneous processes are exothermic.
b. All nonspontaneous processes are endothermic.
c. All spontaneous processes release free energy.
d. Entropy always increases in a spontaneous process.
____ 13. Which variable is NOT required to calculate the Gibbs free-energy change for a chemical reaction?
a. change in enthalpy
c. temperature in kelvins
b. temperature in C
d. change in entropy
Short Answer
14. Calculate the value of K
for the following reaction at equilibrium.
2NClO(g)
2NO(g) + Cl (g)
An analysis of the equilibrium mixture in a 1-L flask gives the following results: NClO, 1.6 mol; NO, 6.4
mol; Cl , 0.49 mol
chemCh19review
Answer Section
MULTIPLE CHOICE
1. ANS: B
OBJ: 18.1.1
2. ANS: C
OBJ: 18.1.2
3. ANS: A
OBJ: 18.1.2
4. ANS: D
OBJ: 18.1.2
5. ANS: C
OBJ: 18.2.1
equilibrium.
6. ANS: B
OBJ: 18.2.3
7. ANS: C
OBJ: 18.2.3
8. ANS: D
OBJ: 18.4.1
9. ANS: C
OBJ: 18.4.2
10. ANS: C
OBJ: 18.4.2
11. ANS: D
OBJ: 18.4.2
12. ANS: C
OBJ: 18.4.3
13. ANS: B
OBJ: 18.4.4
PTS: 1
DIF: L1
REF: p. 544
Describe how to express the rate of a chemical reaction.
PTS: 1
DIF: L1
REF: p. 545
Identify four factors that influence the rate of a chemical reaction.
PTS: 1
DIF: L1
REF: p. 546
Identify four factors that influence the rate of a chemical reaction.
PTS: 1
DIF: L2
REF: p. 547
Identify four factors that influence the rate of a chemical reaction.
PTS: 1
DIF: L1
REF: p. 549 | p. 550
Describe how the amounts of reactants and products change in a chemical system at
PTS: 1
DIF: L1
REF: p. 556
Explain what the value of Keq indicates about the position of equilibrium.
PTS: 1
DIF: L1
REF: p. 556
Explain what the value of Keq indicates about the position of equilibrium.
PTS: 1
DIF: L1
REF: p. 566
Identify two characteristics of spontaneous reactions.
PTS: 1
DIF: L1
REF: p. 570
Describe the role of entropy in chemical reactions.
PTS: 1
DIF: L1
REF: p. 570
Describe the role of entropy in chemical reactions.
PTS: 1
DIF: L2
REF: p. 570
Describe the role of entropy in chemical reactions.
PTS: 1
DIF: L1
REF: p. 571
Identify two factors that determine the spontaneity of a reaction.
PTS: 1
DIF: L2
REF: p. 572
Define Gibbs free-energy change.
SHORT ANSWER
14. ANS:
K
=
=
7.8
PTS: 1
DIF: L3
REF: p. 556 | p. 557
OBJ: 18.2.3 Explain what the value of Keq indicates about the position of equilibrium.