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Topic 9 – Kinetics and Equilibrium

21. Le Chatelier’s Principle – Adding catalyst: Determining effect on reaction

1. Given the reaction
A(g) + B(g) < ============ > 2AB(g)

As a catalyst is added to the above reaction at equilibrium

1) The rate of forward reaction alone will increase
2) The rate of reverse reaction alone will increase
3) The rate of forward and reverse reactions will increase equally
4) The rate of forward and reverse reactions will decrease equally

s 2. Given the reaction
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N2(g) + 3H2(g) < ---------------- > 2NH3(g) + heat
The addition of catalyst
1) Increases the rate of exothermic reaction only
2) Increases the rate of endothermic reaction only
3) Increases the rate of exothermic reaction and decreases the rate of endothermic reaction
4) Increases the both the rates exothermic and endothermic reactions equally

3. When a catalysts is added to the reaction below
C (s) + O2(g) < --------------- > CO2(g)
There will be no change in
1) The rate of forward reaction
2) The rate of reverse reaction
3) The rate of exothermic reaction
4) Equilibrium concentrations of the substances

22. Le Chatelier’s Principle: Determining a stress to equilibrium reactions

1. In the equilibrium reaction:
A(g) + 2B(g) < ========== > AB2(g) + heat
The rate of the forward reaction will increase if there is

1) An increase in pressure 3) An increase in temperature
2) An decrease in pressure
4) A decrease in concentration of B(g)

2. The reaction below is at equilibrium
2Cl2(g) + 2 H2O(g) + 31.2 KJ < ------------- > HCl (g) + O2(g)
Which stress will cause the rate of reverse reaction to increase?
1) Increase in temperature 3) Decrease in HCl(g) concentration
2) Increase Cl2(g) concentration 4) Decrease in H2O(g) concentration

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