Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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Write
the expression for Kc for the reaction below.
Cu2+(aq) + 4 NH3(aq)
⇌
Cu(NH3)42+(aq)
a. | Kc =
 | b. | Kc =
 | c. | Kc =
 | d. | Kc =
 | e. | Kc =
 | | |
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2.
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Write
a balanced chemical equation which corresponds to the following equilibrium constant
expression.
K =
[Fe3+][OH-]3
a. | FeOH2+(s)
⇌ Fe3+(aq) +
OH-(aq) | b. | 3 Fe3+(aq) + 3 OH-(aq)
⇌
3 Fe(OH)3(aq) | c. | Fe(OH)3(aq)
⇌
Fe3+(aq) + 3 OH-(aq) | d. | Fe(OH)3(s)
⇌Fe3+(aq) + 3
OH-(aq) | e. | Fe3+(aq) + 3 OH-(aq)
⇌
3 Fe(OH)3(s) | | |
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3.
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Write
a balanced chemical equation which corresponds to the following equilibrium constant
expression.
K = 
a. | HF(aq)
⇌ F-(aq) + H3O+(aq) | b. | F-(aq) + H3O+(aq)
⇌ HF(aq) +
H2O(l) | c. | HF(aq) + H2O(l)
⇌ F-(aq) +
H3O+(aq) | d. | H+(aq) + OH-(aq)
⇌
H2O(l) | e. | F-(aq) + H3O+(aq)
⇌ HF(aq) | | |
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4.
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At a
given temperature, an equilibrium mixture contains the following concentrations of gases:
[SO3] = 0.054 M, [SO2] = 0.0047 M, and [O2] = 0.58 M. What is the
equilibrium constant, Keq, for the reaction below?
2 SO3(g)
⇌2 SO2(g) +
O2(g)
a. | 4.4 x 10-3 | b. | 5.0 x
10-2 | c. | 11 | d. | 2.0 x 102 | e. | 2.3 x
102 | | |
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5.
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We
place 0.0774 mol N2O4(g) in a 1.00 L flask at a given temperature. After
reaching equilibrium, the concentration of NO2(g) is 0.0068 M. What is
Kc for the reaction below?
N2O4(g)
⇌ 2
NO2(g)
a. | 8.8 x 10-5 | b. | 5.9 x
10-4 | c. | 6.2 x 10-4 | d. | 7.2 x
10-4 | e. | 9.6 x 10-2 | | |
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6.
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A
mixture of 0.200 mol NO2 and 0.200 mol CO is placed in a 1.00 L flask and given time to
equilibrate. Analysis of the equilibrium mixture indicates that 0.134 mol of CO2 is
present. Calculate Kc for the reaction.
NO2(g) + CO(g)
⇌ NO(g) +
CO2(g)
a. | 0.27 | b. | 0.45 | c. | 0.67 | d. | 2.0 | e. | 4.1 | | |
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7.
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At
2010 K, the equilibrium constant, Kc, for the following reaction is 4.0
´
10-4.
N2(g) + O2(g)
⇌ 2
NO(g)
If the equilibrium concentrations of N2 and
O2 are 0.28 mol/L and 0.38 mol/L at 2010 K, what is the equilibrium concentration of
NO? a. | 1.8 x
10-9 M | b. | 2.1 x 10-5 M | c. | 4.3 x
10-5 M | d. | 6.5 x 10-3 M | e. | 6.1 x
10-2 M | | |
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8.
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A
gaseous mixture of NO2 and N2O4 is in equilibrium. If the
concentration of N2O4 is 7.1 ´ 10-4 M, what is the concentration of
NO2?
2 NO2(g)
⇌
N2O4(g) Kc = 170
a. | 1.7 x
10-11 M | b. | 4.2 x 10-6 M | c. | 2.0 x
10-3 M | d. | 4.9 x 102 M | e. | 2.4 x
105 M | | |
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9.
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We have the
following equilibrium,
BaSO4(s)
⇌
Ba2+(aq) + SO42-(aq)
What will happen to [Ba2+] if additional BaSO4
is added to the flask? a. | It will increase. | b. | It will
decrease. | c. | It will not change. | d. | BaSO4 will
dissociate to produce Ba2+ and SO42-
ions. | e. | Cannot tell with the information provided. | | |
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10.
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For the
reaction Ag2S(s) ⇌ 2 Ag+(aq) + S2- (aq), what happens to the
equilibrium position if ammonium sulfide is added? a. | Shifts to the
left. | b. | Shifts to the right | c. | Does nothing
| d. | Doubles. | e. | Halves | | |
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11.
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For the
reaction Ag2S(s) ⇌ 2Ag+ (aq) + S2- (aq), what happens to the
equilibrium position if ammonium sulfide is added? a. | Shifts to the
left. | b. | Shifts to the right | c. | Does nothing
| d. | Doubles. | e. | Halves | | |
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12.
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Consider the
reaction: 2N2O (g) ⇌ O2 (g) + 2N2 (g). Which of the
following will cause a shift in the equilibrium to the right?
1. Add more
N2O
2. Remove
O2
3. Remove N2
a. | 1 and 2
only | b. | 1 and 3 only
| c. | 2 and 3
only | d. | All of 1, 2, and
3 | e. | Neither 1, 2, or 3
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13.
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Consider the
reaction: 2N2O (g)
⇌ O2 (g) + 2N2 (g). Which of the
following will cause a shift in the equilibrium to the left?
1. Remove
N2O
2. Remove
O2
3. Add
N2 a. | 1 and 2
only | b. | 1 and 3 only
| c. | 2 and 3
only | d. | All of 1, 2, and
3 | e. | Neither 1, 2, or 3
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14.
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We have the
following reaction at equilibrium in a flask,
CaSO4(s)
⇌ Ca2+(aq) + SO42-(aq)
What will happen to
[Ca2+] if additional CaSO4 is added to the flask? a. | It will decrease
| b. | It will increase
| c. | It will not change
| d. | It will become
half | e. | Cannot tell with the
information provided. | | |
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15.
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For the
reaction 2N2O (g) ⇌ O2 (g) + 2N2 (g), what happens to the
equilibrium position if the pressure increases? a. | Shifts to the left. | b. | Shifts to the
right | c. | Does nothing | d. | Doubles. | e. | Halves | | |
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16.
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For the
reaction 2N2O (g) ⇌ O2 (g) + 2N2 (g), what happens to the
equilibrium position if the volume decreases? a. | Shifts to the left. | b. | Shifts to the
right | c. | Does nothing | d. | Doubles. | e. | Halves | | |
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17.
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What happens
to the equilibrium position of an exothermic reaction when you add heat? a. | Shifts to the
left. | b. | Shifts to the right | c. | Does nothing
| d. | Doubles. | e. | Halves | | |
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18.
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What happens
to the equilibrium position of an endothermic reaction when you remove heat? a. | Shifts to the
left. | b. | Shifts to the right | c. | Does nothing
| d. | Doubles. | e. | Halves | | |
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19.
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What happens
to the equilibrium position of an endothermic reaction when you add heat? a. | Shifts to the
left. | b. | Shifts to the right | c. | Does nothing
| d. | Doubles. | e. | Halves | | |
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20.
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Which
statement concerning relative rates of reaction is correct for the decomposition of
phosphine?
4 PH3(g)
→
P4(g) + 6 H2(g)
a. | The rate of disappearance of PH3 is 6/4 the rate of
appearance of H2. | b. | The rate of appearance of P4 is equal to the rate of
appearance of H2. | c. | The rate of disappearance of PH3 is ¼
the rate of appearance of P4. | d. | The rate of disappearance of PH3 is 4 times the rate
of appearance of H2. | e. | The rate of appearance of H2 is 6 times the rate of
appearance of P4. | | |
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21.
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The
effect of adding a catalyst to a reaction is to a. | increase the number of collisions between
reactants. | b. | increase the energy of the products. | c. | increase the
equilibrium constant of a reaction. | d. | lower the activation energy of a
reaction. | e. | decrease the enthalpy change of a
reaction. | | |
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22.
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Comparing a
reaction with a catalyst to the same reaction without the catalyst, each of the following statements
is true EXCEPT a. | The rate for the
reaction with a catalyst is faster. | b. | The products are the same. | c. | The catalyzed reaction
follows a different pathway | d. | The uncatalyzed reaction has a smaller value for the equilibrium
constant. | e. | The activation energy for the catalyzed reaction is the same.
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23.
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The
half-life for the radioactive decay of carbon-14 is 5730 years, while that of hydrogen-3 is 12.3
years. This means that a. | hydrogen decays at a faster rate than does
carbon. | b. | carbon decay is a higher order reaction than hydrogen
decay. | c. | more carbon than hydrogen is present in the
world. | d. | the concentration of hydrogen is greater than the concentration of
carbon. | e. | None of the above | | |
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24.
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Which of the
following changes will increase reaction rate?
1. An increase in the concentration of
reactants
2. An increase in
temperature
3. Higher-energy collisions between reacting
molecules a. | 1 and 2 only
| b. | 1 and 3
only | c. | 2 and 3 only
| d. | All of 1, 2, and
3 | e. | Neither 1, 2, or
3 | | |
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25.
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Which of the
following is FALSE about enzymes ? a. | They act as biological catalysts. | b. | They lower the
activation energy of biological reactions. | c. | They increase the
temperature of biological reactions to speed them up. | d. | They are highly
specific in their catalytic activity. | e. | None of the above | | |
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