Le Chatelier's Principle

   1) Consider the following equilibrium, established in a 2-L flask at 30ºC.

CO(g) + H₂O(g) CO₂(g) + H₂(g)     ΔH° = -41.2 kJ

What will happen to the concentration of CO if the temperature is increased?

(a) It will increase.

(b) It will decrease.

(c) It will not change.

 

   2) Consider the following equilibrium, established in a 3-L flask at 1227ºC.

2SO₂(g) + O₂(g) 2SO₃(g)     K = 0.15

What will happen to the concentration of SO₃ if the concentration of SO₂ is increased?

(a) It will increase.

(b) It will decrease.

(c) It will not change.

   3) Consider the following equilibrium, established in a 3-L flask at 50ºC.

NiO(s) + CO(g) Ni(s) + CO₂(g)     

Which direction will the equilibrium shift if the pressure is increased?

(a) To the right.

(b) To the left.

(c) The position of the equilibrium will not change.

   4) Consider the following equilibrium, established in a 1-L flask at 20ºC.

Fe₃O₄(s) + CO(g) 3FeO(s) + CO₂(g)     ΔH° = 19 kJ

What will happen to the concentration of CO if the temperature is decreased?

(a) It will increase.

(b) It will decrease.

(c) It will not change.

   5) Consider the following equilibrium, established in a 1-L flask at 20ºC.

Fe₃O₄(s) + CO(g) 3FeO(s) + CO₂(g)     ΔH° = 19 kJ

What will happen to the concentration of CO₂ if more Fe₃O₄ is added?

(a) It will increase.

(b) It will decrease.

(c) It will not change.

   6) Consider the following equilibrium, established in a 2-L flask at 50ºC.

CS₂(g) + 4H₂(g) CH₄(g) + 2H₂S(g)     

If the pressure is increased, in which direction will the equilibrium shift?

(a) To the right.

(b) To the left.

(c) The position of the equilibrium will not change.

   7) Consider the following equilibrium, established in a 1-L flask at 20ºC.

CO(g) + H₂O(g) CO₂(g) + H₂(g)     ΔH° = -41.2 kJ

What will happen to the concentration of CO₂ if the temperature is decreased?

(a) It will increase.

(b) It will decrease.

(c) It will not change.

    8) Consider the following equilibrium, established in a 2-L flask at 40ºC.

CH₄(g) + 2H₂S(g) CS₂(g) + 4H₂(g)     

If the pressure is decreased, in which direction will the equilibrium shift?

(a) To the right.

(b) To the left.

(c) The position of the equilibrium will not change.