NVCC AL Campus CHM 112 Worksheet
Chapter 14: Chemical Equilibrium
Q1.
Name:________________________
Write the equilibrium expression for following reactions. In each case indicate whether the equilibrium is Homogeneous
or Heterogeneous
1) SO2 (g) + NO2 (g)
SO3(g) + NO (g)
2) 5 Fe2+ (aq) + MnO4- (aq) + 8 H+ (aq)
3) CO32- (aq) + 2 H+ (aq)
4) N2O3 (g)
Q2.
5 Fe3+ (aq) + Mn2+ (aq) + 4 H2O (l)
H2O (l) + CO2 (g)
NO (g) + NO2 (g)
For the reaction:
2 SO2 (g) + O2 (g)
2 SO3 (g) , Kc = 30.0 at 25 C
What is Kp for the reaction at the same temperature?
Q3.
At 298 K, Kc = 1.3 × 10-2 for the reaction
2 NO (aq) + Br2 (g)
2 NOBr (g)
What is the value of Kc for the following reaction?
NOBr (g)
NO (aq) + ½ Br2 (g)
NVCC AL Campus CHM 112 Worksheet
Q4.
Consider the equilibrium reaction H2 (g) + I2 (g)
2 HI (g); Kc= 50.5
A vessel contains 0.010 M HI, 0.0050 M H2 and 0.015 M I2.
Is this mixture at equilibrium?
If not, then which direction will the reaction proceed to attain equilibrium?
Q5.
For the reaction: CO (g) + H2O (g)
CO2 (g) + H2 (g) , Kp = 4.0
An equilibrium mixture was found to contain 0.60 atm CO, 0.20 atm of steam, and 0.50 atm CO2. What is the
equilibrium partial pressure of H2 in this mixture?
NVCC AL Campus CHM 112 Worksheet
Q6.
Given the following information
CoO(s) + H2 (g)
CoO(s) + CO (g)
Co (s) + H2O (g)
Kc = 67
Co (s) + CO2 (g)
Kc =490
Calculate Kc for the following reaction
2H2 (g) + 2CO2 (g)
Q7.
2CO (g) + 2H2O (g)
Considere the reaction: NH4HS (s)
NH3 (g) + H2S (g), Kc = 1.2 x 104.
What are the equilibrium concentrations of NH3 and H2S if a solid sample of NH4HS is placed in a reaction vessel
and decomposes until equilibrium gets established?
NVCC AL Campus CHM 112 Worksheet
Q8. Consider the equilibrium reaction
N2O4 (g)
ΔH° = 58.0 kJ
2 NO2 (g)
In which direction will the equilibrium shift when the following changes are made? Explain your reasoning.
(A) N2O4 (g) is added?
(B) NO2 (g) is removed?
(C) The volume of the reaction vessel is increased?
(D) The temperature is decreased?
(E) The total pressure is increased by adding some N2 (g)
Q9.
Consider the following equilibrium
6CO2 (g) + 6 H2O(l)
C6H12O6 (s) + 6 O2(g)
ΔH = 2816 kJ
How will each of the following changes affect the equilibrium yield of C6H12O6. Explain your reasoning.
1) Increasing Pressure of CO2
2) Increasing temperature
3) Removing CO2
4) Decreasing the volume of the reaction vessel
5) Removing part of C6H12O6 (s)
6) Adding a catalyst
NVCC AL Campus CHM 112 Worksheet
Q10.
A 7.24 g sample of IBr is placed in a 0.225 L vessel and heated to 500. K. The following reaction takes place.
2 IBr (g)
I2 (g) + Br2(g)
At equilibrium, the partial pressure of Br2 is 3.01 atm. Calculate Kp for this reaction.
Calculate Kc for the same reaction.
Q11.
Consider the reaction
2 SO3 (g)
2 SO2 (g) + O2 (g)
In an experiment, SO3 (g) at 1.0 atm was placed in an empty reaction vessel. After equilibrium was established, the
vessel contained 0.60 atm of SO2 (g). Calculate Kp for the reaction.
NVCC AL Campus CHM 112 Worksheet
Q12.
Consider the reaction. 2NO2 (g)
2NO (g) + O2 (g)
A 0.240 mol sample of NO2 was placed in an empty2.00-L flask at 700 K. At equilibrium, the flask contained 0.179 mol
of NO2. Calculate Kc for the reaction.
Q13.
Consider the following reaction
PCl5 (g)  PCl3 (g) + Cl2 (g)
ΔH° = +87.9 kJ
In which direction will the equilibrium be shifted by the following changes?
a) Adding PCl3
b) Removing Cl2
c) Removing PCl5
d) Adding a catalyst
e) Increasing the temperature of the reaction mixture
f) Adding He gas to the reaction mixture at constant volume
g) Decreasing the volume of the reaction vessel
NVCC AL Campus CHM 112 Worksheet
Q14.
At 600 K, Kp = 4.10 × 10-3 for the following reaction
COCl2 (g)
CO (g) + Cl2 (g)
Calculate their equilibrium pressures of all the components in the system if the starting pressure of COCl 2 was 0.124 atm
Q15.
For the reaction 2 NO2 (g)
2 NO (g) + O2 (g),
Kp = 6.5×10-6 at 450 C.
If a reaction vessel at this temperature initially contains 0.500 atm of NO2, what are the pressures of all species at
equilibrium?