Section 18.2
Factors Affecting Chemical Equilibrium
Practice Test
1.
Which of the following states that an equilibrium system that is disturbed will respond in a manner to restore equilibrium?
a.
Le Châtelier’s principle
b.
Boyle’s law
c.
Charles’s law
d.
Dalton’s law
Hint
2.
For the system, H2(g) + CO2(g) → H2O(g) + CO(g) at equilibrium, the addition of H2(g) would cause ____________.
a.
only more H
2
O to form
b.
only more CO to form
c.
more H
2
O and CO to form
d.
only more CO
2
to form
Hint
3.
For the reaction, 2SO
2
(g) + O
2
(g) → 2SO
3
(g) at equilibrium, the removal of O
2
would cause _______________.
a.
the concentration of SO
2
to increase, and the concentration of SO
3
to increase
b.
the concentration of SO
2
to increase, and the concentration of SO
3
to decrease
c.
the concentration of SO
2
to decrease, and the concentration of SO
3
to increase
d.
the concentration of SO
2
to decrease, and the concentration of SO
3
to decrease
Hint
4.
For the reaction, 2SO
2
(g) + O
2
(g) → 2SO
3
(g) at equilibrium, what will be the effect on the net amount of SO
3
present if the volume of the container is increased?
a.
The concentration of SO
3
will increase.
b.
The concentration of SO
3
will decrease.
c.
The concentration of SO
3
will remain the same.
d.
This question cannot be answered without knowing the value of Keq.
Hint
5.
For the reaction, 2SO
2
(g) + O
2
(g) → 2SO
3
(g) + heat, at equilibrium, what will be the effect on the net amount of SO
3
present if the temperature of the container is increased?
a.
The concentration of SO
3
increases.
b.
The concentration of SO
3
decreases.
c.
The concentration of SO
3
remains the same.
d.
This question cannot be answered without knowing the value of Keq.
Hint
6.
For the gas phase reaction, SO
2
(g) + ½O
2
(g) → SO
3
(g), ΔH° = -1.6 × 102 kJ for the forward reaction. To increase the yield of SO
3
, the reaction should be run at ________.
a.
high pressure and high temperature
b.
high pressure and low temperature
c.
low pressure and high temperature
d.
low pressure and low temperature
Hint
7.
For the reaction, H
2
(g) + Cl
2
(g) → 2HCl(g) + heat, what will be the effect on the equilibrium constant,
K
eq
, if the pressure of the vessel is decreased at constant temperature?
a.
K
eq
increases
b.
K
eq
decreases
c.
K
eq
does not change
d.
The question cannot be answered without knowing the initial value of
K
eq
.
Hint
8.
For the reaction, 2NOCl(g) +75 kJ → 2NO(g) + Cl
2
(g), which of the following will shift the reaction to the left?
a.
add a catalyst
b.
heat the reaction vessel
c.
decrease the volume of the container
d.
add more NOCl
Hint
9.
For the reaction, 2Cl
2
(g) + 2H
2
O(g) + heat → 4HCl(g) + O
2
(g), which of the following will shift the equilibrium to produce more HCl?
a.
add more Cl
2
b.
lower the temperature of the reaction
c.
decrease the volume of the reaction vessel
d.
add more O
2
Hint
10.
Which of the following would force the forward reaction to completion?
CaCO
3
(s) + 2H
3
O
+
(aq) → Ca
2+
(aq) + 3H
2
O(l) + CO
2
(g)
a.
add base to neutralize the H
3
O
+
b.
add more Ca
2+
to the mixture
c.
conduct the experiment in an open container
d.
add CO
2
to the mixture
Hint
