Quiz # 3 – Yield/Graphing/LeChatelier’s Principle
1. When a catalyst is added to an equilibrium system, the forward reaction
A. Increases and the reverse decreases
B. Decreases and the reverse decreases
C. Decreases and the reverse increases
D. Increases and the reverse increases
2. Consider the following concentration versus time graph for the equilibrium
N2O4(g)
2NO2(g)
At time= “t”, which one of the following stresses occurred
A. Catalyst was added
B. Pressure was changed
C. Temperature was changed
D. Concentration of NO2 was changed
3. Which of the following reactions will shift left when pressure is increased and when
temperature is decreased?
A. N2(g) + 2O2(g) + heat
2NO2(g)
B. N2(g) + 3H2(g)
2NH3(g) + heat
C. CH4(g) + H2O(g) + heat
CO(g) + 3H2(g)
D. CS2(g) + 4H2(g)
CH4(g) + 2H2S(g) + heat
4. Consider the following graph, which relates to this equilibrium
N2(g) + 3H2(g)
A. Addition of N2
2NH3(g) ∆H = -92kJ
B. Removal of H2
C. Decrease in temperature
D. Decrease in reaction volume
5. Consider the following equalibrium
CH4(g) + H2O(g) + heat
CO(g) + 3H2(g)
In which of the following will both stresses shift the equilibrium right
A. A decrease in temperature and a decrease in volume
B. An increase in temperature and a decrease in volume
C. A decrease in temperature and an increase in volume
D. An increase in temperature and an increase in volume
6. Consider the following equilibrium system
N2(g) + 3H2(g)
2NH3(g) + 92 kJ
A. Low pressure and low temperature
B. Low pressure and high temperature
C. High temperature and low pressure
D. High pressure and high temperature
7. Consider the following equilibrium system
NH3(aq) + H2O(l)
NH+4(aq) + OH--(aq)
Which of the following when added to the above equilibrium system would cause an
increase in [OH-]
A. NH3
B. H2O
C. NH4+
D. HCl
8. Consider the following reversible reaction
Fe3+(aq) + SCN-(aq)
FeSCN2+(aq)
A solution of Fe(NO3)3 is added to a solution of KSCN. Which one of the following
statements describes
the changes in forward and reverse reaction rates as the reaction moves towards
equilibrium?
A. Forward and reverse rates increase
B. Forward and reverse rates decrease
C. Forward rate increases and reverse rate decrease
D. Forward rate decreases and reverse rate increase
9. Consider the following equilibrium:
N2(g) + O2(g)
2NO(g)
∆H= + 181 kJ
When the temperature is decreased, the equilibrium
A. Shifts left and [NO] decreases
B. Shifts left and [NO] increases
C. Shifts right and [NO] increases
D. Shifts right and [NO] decreases
10. Consider the following equilibrium
N2(g) + 3H2(g)
2NH3(g) + 92 kJ
In which of the following will both changes shift the equilibrium right?
A. An increase in volume and a decrease in temperature
B. An increase in volume and a increase in temperature
C. A decrease in volume and a decrease in temperature
D. A decrease in volume and an increase in temperature
11. Consider the following equilibrium
CaCO3(s) + 556 kJ
The equilibrium will shift to the right
A. CO2 is added
B. CO2 is removed
C. The temperature is increased
D. The temperature is decreased
CaCO(s) + CO2(g)
12. Consider the following equilibrium
SO2(g) + NO2(g)
SO3(g) + NO(g) + energy
The equilibrium does not shift with a change in the
A. Volume
B. Temperature
C. Concentration of products
D. Concentration of reactants
13. Consider the following equilibrium
2Hl(g)
H2(g) + I2(g)
At constant temperature and volume, more I2 is added to the above equilibrium. A
new
state of equilibrium results from a shift to the
A. Left with a net decrease in [H2]
B. Left with a net increase in [H2]
C. Right with a net increase in [H2]
D. Right with a net decrease in [H2]
14. Consider the following equilibrium
CO(g) + 2H2(g)
CH3OH(g) + 91 kJ
A change in temperature of the above system increases the value of the equilibrium
constant.
The new state of equilibrium was established by a shift
A. Left as a result of a decrease in temperature
B. Right as a result of a decrease in temperature
C. Left as a result of an increase in temperature
D. Right as a result of an increase in temperature