Name __________________________________________________________Class _______________ Date ______________
Write the equilibrium expressions (K eq
) for the following reactions
1.
2CO(g) ↔ C(s) + CO
2
(g)
2.
N
2
O
4
(g) ↔ 2NO
2
(g),
3.
2ICl(g) ↔ I
2
(g) + Cl
2
(g),
4.
Fe
2
O
3
(s) + 3H
2
(g) ↔ 2Fe(s) + 3H
2
O(g)
5.
2CO(g) + 4H
2
O(g) ↔ 3O
2
(g) + 2CH
4
(g)
6.
P
4
(s) + 6NO(g) ↔ P
4
O
6
(s) + 3N
2
(g)
eq
1.
What is the equilibrium expression for the following reaction? SnO
2
(s) + 2CO(g) ↔ Sn(s) + 2CO
2
(g)
2.
At equilibrium the following concentrations are recorded: 20.0 M of H
2
, 18.0 M of CO
2
, 12.0 M H
2
O, and 5.9 M of CO at 427˚C.
What is the value of K
(eq)
at this temperature for the following reaction? CO
2
(g) + H
2
(g) ↔ CO(g) + H
2
O(g)
3.
At equilibrium a mixture of N
2
, H
2
, and NH
3
gas at 500˚C is determined to consist of 0.602 M N
2
, 0.420 M H
2
, and 0.113 M of
NH
3
. What is the equilibrium constant at this temperature? Does this equilibrium favor the reactants or the products?
N
2
(g) + 3H
2
(g) ↔ 2NH
3
(g)
4.
Given the equilibrium concentrations of 0.15 M NO, 0.12 M H
2
and 1.6 M N
2
, Calculate the equilibrium constant for the following reaction. Does this reaction favor the reactants or the products? 2NO(g) + 2H
2
(g) ↔ N
2
(g) + 2H
2
O(l)
5.
What is the equilibrium constant for the following reaction if the equilibrium concentrations for the gases are 0.3 M for C
2
H
6
, 0.6 M for O
2
, 1.3 M for CO
2
and 1.8 M for H
2
0? Does the reaction favor the reactants or products?
2C
2
H
6
(g) + 7O
2
(g) 4CO
2
(g) + 6H
2
O(g)
6.
Nitrogen dioxide reacts to form dinitrogen tetraoxide. What is the equilibrium concentration of N
2
O
4
, if the K eq
= 4.70 and the equilibrium concentration of NO
2
is 0.0310 M? 2NO
2
(g) ↔ N
2
O
4
(g)

Name __________________________________________________________Class _______________ Date ______________
Practice 14.3 Le Chatelier's Principle
1.
Predict which way the following equilibrium systems will shift when the total pressure is increased .(NOTE: Some may have no shift) a). N
2
(g) + O
2
(g) ↔ 2NO(g) ......................... Answer__________________ b). 2SO
2
(g) + O
2
(g) ↔ 2SO
3
(g) ...................... Answer__________________ c).
4NH
3
(g) + 5O
2
(g) ↔ 4NO(g) + 6H
2
O(g) ....... Answer__________________
2.
Which way will the following equilibrium shift if the total pressure on the system is decreased ?
2C
2
H
6
(g) + 7O
2
(g) ↔ 4CO
2
(g) + 6H
2
O(g) Answer__________________
3.
Hydrogen peroxide is decomposed as follows: H
2
O
2
(l) ↔ H
2
(g) + O
2
(g) D H = +187 kJ
Predict the direction of equilibrium shift by each of the following imposed changes:
Increase the [H
2
] ........................................ Answer _________________________
Decrease the [O
2
] ....................................... Answer _________________________
Decrease the total pressure ........................ Answer _________________________
Increase the temperature ............................ Answer _________________________
4.
Consider the following equilibrium and state which way (left or right) the equilibrium shifts when each of the changes below are made.
Heat + CH
4
(g) + 2H
2
S(g) ↔ CS
2
(g) + 4H
2
(g)
CH
4
gas is added ................................................... Answer __________________
CS
2
gas is removed................................................ Answer __________________
H
2
gas is added ...................................................... Answer __________________
The total volume of the container is decreased ........ Answer __________________
The temperature is increased .................................. Answer __________________
The total pressure is decreased ............................... Answer __________________
Helium gas is added to increase the total pressure.... Answer __________________
5.
Using the following equilibrium, state what would happen to the equilibrium when each of the following changes are made:
CO(g) + 2H
2
(g) ↔ CH
3
OH(g) D H = -75.2 kJ
CO gas is added to the container ............................ Answer __________________
The temperature is increased .................................. Answer __________________
The total pressure of the system is increased.......... Answer __________________
H
2
gas is removed from the system......................... Answer __________________
The total volume of the container is increased......... Answer __________________
6.
For the reaction: 2NO(g) + Cl
2
(g) ↔ 2NOCl(g) D H= -77 kJ
State the optimal pressure and temperature conditions necessary for maximum production of NOCl.( high or low?
)
____________________pressure
___________________ temperature
7.
For the reaction: 3H
2
(g) + N
2
(g) ↔ 2NH
3
(g) + heat
State the optimal conditions for a high yield of ammonia (NH
3
) . ( high or low?
)
_____________________pressure
_____________________ temperature
8.
Given the following equilibrium system, state which way the equilibrium will shift when the changes below are made:
2C
2
H
6
(g) + 7O
2
(g) ↔ 4CO
2
(g) + 6H
2
O(g) + heat
The volume of the container is halved..................... Answer __________________
The temperature is decreased ................................. Answer __________________
CO
2
is added to the container.................................. Answer __________________
The total pressure is increased ............................... Answer __________________
O
2
gas is removed from the system ........................ Answer __________________
Neon gas is added to increase the total pressure ..... Answer __________________