EP 5 Review

ep 5 review

Matching

Match each item with the correct statement below.
a. activated complex d. activation energy
b. reaction rate e. free energy
c. inhibitor


____ 1. the minimum energy colliding particles must have in order to react

____ 2. arrangement of atoms at the peak of an energy barrier

____ 3. the number of atoms, ions, or molecules that react in a given time to form products

____ 4. a substance that interferes with a catalyst

____ 5. energy available to do work

Match each item with the correct statement below.
a. spontaneous reaction d. reaction mechanism
b. entropy e. elementary reaction
c. chemical equilibrium


____ 6. when the forward and reverse reactions take place at the same rate

____ 7. a reaction that releases free energy

____ 8. the measure of disorder

____ 9. Reactants are converted to products in a single step.

____ 10. includes all elementary reactions of a complex reaction

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.

____ 11. Activation energy is ____.
a. the heat released in a reaction
b. an energy barrier between reactants and products
c. the energy given off when reactants collide
d. generally very high for a reaction that takes place rapidly


____ 12. Why does a higher concentration make a reaction 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.


____ 13. What happens to a catalyst in a reaction?
a. It is unchanged. c. It is incorporated into the reactants.
b. It is incorporated into the products. d. It evaporates away.


____ 14. Consider the reaction N (g) 3H (g) 2NH (g). What is the effect of decreasing the volume on the contained gases?
a. The reaction shifts toward the product gas.
b. The system reacts by increasing the number of gas molecules.
c. The pressure on the gases decreases momentarily.
d. Ammonia is consumed in the reaction.


____ 15. What happens to a reaction at equilibrium when more reactant is added to the system?
a. The reaction makes more products. c. The reaction is unchanged.
b. The reaction makes more reactants. d. The answer cannot be determined.


____ 16. In an endothermic reaction at equilibrium, what is the effect of raising the temperature?
a. The reaction makes more products. c. The reaction is unchanged.
b. The reaction makes more reactants. d. The answer cannot be determined.


____ 17. What is the effect of adding more water to the following equilibrium reaction?
CO + H O H CO
a. More H CO is produced.
b. CO concentration increases.
c. The equilibrium is pushed in the direction of reactants.
d. There is no effect.


____ 18. In an equilibrium reaction with a K of 1 10 , the ____.
a. reactants are favored c. the products are favored
b. reaction is spontaneous d. reaction is exothermic


____ 19. The K of a reaction is 4 10 . At equilibrium, the ____.
a. reactants are favored
b. products are favored
c. reactants and products are present in equal amounts
d. rate of the forward reaction is much greater than the rate of the reverse reaction


____ 20. The amount of disorder in a system is measured by its ____.
a. activation energy c. equilibrium position
b. entropy d. K


____ 21. Which one of the following systems has the highest entropy?
a. 10 mL of water at 10 C
b. 10 mL of water at 50 C
c. 10 mL of water at 100 C
d. All have the same entropy because all are water.


____ 22. If a system is left to change spontaneously, in what state will it end?
a. the same state in which it began
b. the state with lowest possible energy
c. the state with the maximum disorder
d. the state with the lowest possible energy consistent with the state of maximum disorder


____ 23. The melting of ice at temperatures above 0 C ____.
a. liberates heat c. is not favorable
b. is not spontaneous d. is endothermic


____ 24. What determines whether or not a reaction is spontaneous?
a. change in molar volume and heat change
b. change in enthalpy only
c. enthalpy change and entropy change
d. change in entropy only


____ 25. 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


____ 26. What is the rate law for the following reaction?
A + 2B  C + D
a. rate = k[A][B] c. rate = k[A][B]
b. rate = k[A] [B] d. rate = k[A] [B]


____ 27. What is the order of the following reaction? A + 2B  C + D
a. zero c. second
b. first d. third


____ 28. If a reaction rate decreases by a factor of one-ninth when a reactant concentration is decreased by one-third, what is the order of the reaction with respect to that reactant?
a. fourth c. second
b. third d. first


____ 29. When nitrous oxide is converted to nitrogen and oxygen, what is the term used to describe the oxygen atoms formed?
a. reactants c. activated complexes
b. products d. intermediates


____ 30. For a complex reaction, the reaction progress curve ____.
a. is a flat line c. has several hills and valleys
b. has only one peak d. shows energy versus pressure


Essay

31. Explain the effects of reactant concentration and particle size on the rate of a reaction.

32. What is the effect of a catalyst on the rate of a reaction? Give an example of a catalyst.

ep 5 review
Answer Section

MATCHING

1. ANS: D DIF: L1 REF: p. 543 OBJ: 18.1.1

2. ANS: A DIF: L1 REF: p. 544 OBJ: 18.1.1

3. ANS: B DIF: L1 REF: p. 542 OBJ: 18.1.1

4. ANS: C DIF: L1 REF: p. 547 OBJ: 18.1.2

5. ANS: E DIF: L1 REF: p. 566 OBJ: 18.4.1

6. ANS: C DIF: L1 REF: p. 550 OBJ: 18.2.1

7. ANS: A DIF: L1 REF: p. 567 OBJ: 18.4.1

8. ANS: B DIF: L1 REF: p. 569 OBJ: 18.4.2

9. ANS: E DIF: L1 REF: p. 578 OBJ: 18.5.2

10. ANS: D DIF: L1 REF: p. 578 OBJ: 18.5.2

MULTIPLE CHOICE

11. ANS: B DIF: L1 REF: p. 543 OBJ: 18.1.1

12. ANS: A DIF: L1 REF: p. 545 OBJ: 18.1.2

13. ANS: A DIF: L1 REF: p. 546 OBJ: 18.1.2

14. ANS: A DIF: L2 REF: p. 554 OBJ: 18.2.2

15. ANS: A DIF: L2 REF: p. 552, p. 553
OBJ: 18.2.2

16. ANS: A DIF: L2 REF: p. 554 OBJ: 18.2.2

17. ANS: A DIF: L2 REF: p. 552, p. 553
OBJ: 18.2.2

18. ANS: C DIF: L1 REF: p. 556 OBJ: 18.2.3

19. ANS: A DIF: L1 REF: p. 556 OBJ: 18.2.3