TABLE 1
1. N
2
(g) + 3H
2
(g) ↔ 2NH
3
(g) + HEAT
Explain the effect of each of the following changes upon the system in terms of Le Chatelier 's Principle and a shift towards either the product or reactant side.
1 . More hydrogen is added to the system R .
2 . Ammonia is removed from the system . R
3 . Nitrogen is removed from the system . L
4 . The temperature is raised . L
5 . The pressure of the system is decreased by doubling the total volume . L
TABLE 2
58.
Predict the shift in the equilibrium position that will occur for each of the following reactions when the volume of the reaction container is increased.
a. N
2
(g) + 3 H
2
(g)
⇌
2 NH
3
(g) L b. PCl
5
(g) ↔ PCl
3
(g) + Cl
2
(g) - R c. H
2
(g) + F
2
(g)
⇌
2HF(g) NC d. COCl
2
(g)
⇌
CO(g) + Cl
2
(g) R e. CaCO
3
(s) ↔ CaO(s) + CO
2
(g) R

TABLE 3
59. CO(g) + H
2
O(g) → H
2
(g) + CO
2
(g)
How will this system at equilibrium shift in each of the following cases: a. Gaseous CO
2
is removed R b. water vapor is added R c. the pressure is increased by adding He gas. NC d. the temperature is increased (the reaction is exothermic) L e. the pressure is increased. NC
TABLE 4
60. What will happen to the number of moles of SO
3
in equilibrium with SO
2
and O
2
in the reaction:
2 SO
3(g)
⇌
2 SO
2(g)
+ O
2(g)
∆H ˚ = 197 KJ a. oxygen gas is added
L ↑n SO
3 b. the pressure is increased by decreasing the volume of the reaction container
L ↑n SO
3 c. the pressure is increased by adding argon gas - NC d. the temperature is decreased L ↓ n SO
3 e. gaseous sulfur dioxide is removed. R ↓ n SO
3

TABLE 5
14.12. Consider the following equilibrium systems: a) 2PbS (s) + 3O
2
(g) ↔ 2PbO (s) + 2SO
2
(g) R b) PCl
5
(g) ↔ PCl
3
(g) + Cl
2
(g) L c) H
2
(g) + CO
2
(g) ↔ H
2
O (g) + CO (g) NC d) 2NO Cl (g) ↔ 2NO (g) + Cl
2
(g) L
Predict the direction of the net reaction in each case as a result of increasing the pressure (decreasing the volume) on the system at constant temperature.
TABLE 6
14.13. Consider the following equilibrium process between dinitrogen tetrafluoride (N
2
F
4
) and nitrogen difluoride (NF
2
):
N
2
F
4
(g) ↔ 2NF
2
(g)
∆H ˚ = 38.5KJ/mol
Predict changes in the equilibrium if a) The reacting mixture is heated at constant
Volume. R b) Some N
2
F
4
(g) is removed. T and V constant L c) Pressure is decreased at constant T. R d) A catalyst is added to the reacting mixture. NC

TABLE 7
1. Which of the following changes will cause an increase in the rate of the reaction below? a. decreasing the temperature b. increasing the concentration of HBr c. decreasing the concentration of C
6
H
6 d. increasing the concentration of Br
2
2. If the reaction below takes place inside a sealed reaction chamber, then which of these procedures will cause a decrease in the rate of reaction?
2CO + O
2
→ 2CO
2
A. removing the CO
2
as it is formed
B. raising the temperature of the reaction chamber e. increasing the volume inside the reaction chamber f. adding more CO to the reaction chamber
The most effective ways to increase the rate of a reaction are to.
8.b
A) decrease the temperature and increase the reactant concentrations.
B) increase the particle size and increase the temperature.
C) increase the temperature and decrease the particle size.
D) increase the temperature and decrease the pressure.

TABLE 8
When the rate of a reaction increases, __________. 8.a
A) there is a decrease in the concentration of the reactants with time
B) there is a decrease in the concentration of the products with time
C) there is an increase in the concentration of the reactants with time
D) there is an increase in the concentration of the reactants and a decrease in the concentration of the products with time
2SO
2
(g) + O
2
(g)  2SO
3
(g)
Δ
H = -280J
How does the amount of O
2
change if … a. Increase SO
2
↓ b. Increase Temperature ↑ c. Remove SO
3
↓ d. Reduce the volume of the container ↓ e. Add a Catalyst NC

TABLE 9
1998 D
C (s) + H
2
O (g)

CO (g) + H
2
(g)
 Hº = +131kJ
A rigid container holds a mixture of graphite pellets (C (s) ),
H
2
O (g) , CO (g) , and H
2
(g) at equilibrium. State whether the number of moles of CO (g) in the container will increase, decrease, or remain the same after each of the following disturbances is applied to the original mixture. For each case, assume that all other variables remain constant except for the given disturbance. Explain each answer with a short statement.
(a) Additional H
2
(g) is added to the equilibrium mixture at constant volume. DECREASE
(b) The temperature of the equilibrium mixture is increased at constant volume. INCREASE
(c) The volume of the container is decreased at constant temperature.
DECREASE
(d) The graphite pellets are pulverized. NC
HONORS CHEMISTRY
3. A sample of solid ammonium chloride was placed in an evacuated container and then heated so that it decomposed to ammonia gas and hydrogen chloride gas. After heating , the total pressure in the container was found to be 4.4 atm.
Calculate Kp at this temperature for the decomposition reaction.
NH
4
Cl(s)
⇌
NH
3
(g) + HCl(g)

NH
4
Cl(s)
⇌
NH
3
(g) + HCl(g)
K
P
= P
NH
3
× P
HCl
For this system to reach equilibrium, some of the NH
4
Cl(s) decomposes to form equal moles of NH
3
(g) and HCl(g) at equilibrium. Because mol HCl = mol NH
3
, the partial pressures of each gas must be equal to each other.
At equilibrium: P total
= P
NH
3
+ P
HCl
and
P
NH
3
= P
HCl
P total
= 4.4 atm = 2 P
NH
3
, 2.2 atm = P
NH
3
= P
HCl
;
K p
= (2.2)(2.2) = 4.8
Answer
(a) CO will decrease. An increase of hydrogen gas molecule will increase the rate of the reverse reaction which consumes CO. A LeChatelier Principle shift to the left.
(b) CO will increase. Since the forward reaction is endothermic (a

H > 0) an increase in temperature will cause the forward reaction to increase its rate and produce more CO. A
LeChatelier Principle shift to the right.
(c) CO will decrease. A decrease in volume will result in an increase in pressure, the equilibrium will shift to the side with fewer gas molecules to decrease the pressure,

, a shift to the left.
(d) CO will remain the same. Once at equilibrium, the size of the solid will affect neither the reaction rates nor the equilibrium nor the concentrations of reactants or products.

4
. A mixture of 0.500 mol H
2
and 0.500 mol I
2
was place in a 1.00 L stainless-steel flask at 430 C.
The equilibrium constant K c
for the reaction H
2
(g) + I
2
(g)
⇌
2HI(g) is 54.3 at this temperature.
Calculate the concentrations of H
2
, I
2
, and HI at equilibrium.
(chang 14.9)