Chemical Equilibrium Worksheet

1) Define Chemical Equilibrium—

2) Write the expression for the equilibrium constant for the following reactions:

aA (g) + bB (g) ⇌ cC (g) + dD (g)

aA (l) + bB (l) ⇌ cC (g) + dD (g)

aA (l) + bB (s) ⇌ cC (aq) + dD (aq)

aA (s) + bB (g) ⇌ cC (l) + dD (g)

aA (l) + bB (g) ⇌ cC aq) + dD (g)

3) What happens to the equilibrium coefficient K if all stoichiometric coefficients are…

Multiplied by two?

Divided by 2?

Multiplied by 5?

4) If I add reaction A with equilibrium coefficient Ka to reaction B with equilibrium

coefficient Kb, what is the new equilibrium coefficient for the resulting reaction (In terms

of Ka and Kb)?

5) Given the following:

HNO2(aq) ⇌ H+(aq) + NO2-(aq) Ka = 4.5*10-4

H2 SO3(aq) ⇌ H+(aq) + HSO3-(aq) Kb = 1.1*10-9

What is the value of K for the following reaction?

HNO2(aq) + HSO3-(aq) ⇌ H2 SO3(aq) + NO2-(aq)

6) Given the reactions

HF (aq) ⇌ H+(aq) + F-(aq) Ka = 6.8*10-4

H2C2O4(aq) ⇌ 2H+(aq) + C2O42- (aq) Kb = 3.8*10-6

What is the value of K for the following reaction?

2 HF (aq) + C2O42- (aq) ⇌ 2F-(aq) + H2C2O4(aq)

7) What is Le Chatlier’s Principle?

8) For the exothermic reaction 4NH3 (g)+ 5O2(g) ⇌4NO(g) + 6H2O(g), which direction will the equilibrium shift for the following changes :

a. Adding more water vapor?

b. Increasing the temperature?

c. Increasing the volume of the reaction vessel?

d. Removing O2(g)?

e. Adding 1 atm of an inert gas to the reaction vessel?

9) What is Q?

10) Which direction will the reaction shift if Q<K? and if Q>K?

13) At 448℃, the equilibrium constant Kc for the reaction H2(g) + I2(g) ⇌ 2HI(g) is

K=50.5. Predict in what direction the reaction procedes to reach equilibrium if we have 2.0*10-2 mol H2, 3.0*10-2 mol I2, and 1.0*10^-4 mol HI in a 2.00 L container.