Le Chatelier’s Principle
Chemistry
Name:
Class:
For the following reactions, determine if the reaction will shift to the right, left, or
no change. Briefly explain your choice.
1. Assume that the reaction below is at equilibrium. A stress is then applied—the
volume is decreased. Indicate how the system will respond to the stress.
H2CO (g) + H2O(g) <=> CH4 (g) + O2(g)
2. Assume that the reaction below is at equilibrium. A stress is then applied -- The
volume is increased. Indicate how the system will respond to the stress.
CH4 (g) + O2(g) <=> H2CO(g) + H2O(g).
3. Assume that the reaction below is at equilibrium. A stress is then applied –
CO2 is added. Indicate how the system will respond to the stress.
CaCO3 (s) <=> CaO(s) + CO2 (g)
4. Assume that the reaction below is at equilibrium. A stress is then applied -NOBr is added. Indicate how the system will respond to the stress.
2NO(g) + Br2(g) <=> 2NOBr(g)
5. Assume that the reaction below is at equilibrium. A stress is then applied – NO3
is added. Indicate how the system will respond to the stress.
NO3(g) <=> NO(g) + O2 (g)
6. Assume that the reaction below is at equilibrium. A stress is then applied – SO3
is added. . Indicate how the system will respond to the stress.
2SO2(g) + O2(g) ,<=> 2SO3(g)
7. Assume that the reaction below is at equilibrium. A stress is then applied –
N2O4 is removed. Indicate how the system will respond to the stress.
2 N2O4 (g) <=> 2N2O(g) + 3O2(g)
8. Assume that the reaction below is at equilibrium. A stress is then applied -- The
volume is increased. Indicate how the system will respond to the stress.
COCl2(g) <=> CO(g) + Cl2(g)
9. Assume that the reaction below is at equilibrium. A stress is then applied – CS2
is removed. . Indicate how the system will respond to the stress.
CS2g) + 4H2 (g) <=> CH4(g) + 2H2S(g)
Le Chatlier’s Principle – Part 2
Chemistry
Name:
Class:
1. The following reaction is at equilibrium:
CS2 (g) + 3Cl2 (g)  CCl4 (g) + S2Cl2 (g) + Energy
Predict the effect of the following changes to the system on the direction of
equilibrium. (Right, left, no change)
a. The pressure on the system is doubled by halving the volume of the
container.
b. CCl4 is removed as it is generated.
c. Heat is added to the system.
d. Additional Cl2 is added to the container.
2. Predict the effect of the following changes to the system on the direction of
equilibrium. (Right, left, no change)
Energy + N2 (g) + 6HCl (g)  2NH3 (g) + 3Cl2 (g)
a.
b.
c.
d.
Triple the volume of the system.
The amount of nitrogen is doubled.
The flask containing the reaction is placed in an ice bath or cooled.
Solid silver is added to the container and reacts with Cl2 to form AgCl
solid.
3. For the following reaction
Cr2O72- (aq) + H2O (l)  2CrO42- (aq) + 2H+ (aq)
a. Explain why an increase in pressure on the system has no effect on the
reaction.
b. When OH- is added, the reaction shifts strongly to the right. How could you
explain this? (Hint: Remember that OH- combines with H+ to make water.)
4. If you wanted to use the following reaction for the production of methanol,
CH3OH, commercially, would high or low temperatures favor the maximum
yield? Why?
CO (g) +2H2 (g)  CH3OH (g) + Energy
5. The reaction for the dissolution of Fe(OH)2 is:
Fe(OH)2 (s)  Fe2+ (aq) + OH- (aq)
a. To a saturated solution of Fe(OH)2, you add OH-. What is the shift in
equilibrium and would you be able to see the change?
b. If additional Fe(OH)2 is added to the beaker, would there be a shift in
equilibrium?
c. If you added an acid (H+ ions) to the solution, would this shift the
equilibrium at all? If so, why and how?