Question

Part A The Haber process is typically carried out at a temperature of approximately 500∘C. What would happen to the rate of the forward reaction if the temperature were lowered to 100∘C? The reaction rate would . SubmitHintsMy AnswersGive UpReview Part Part B What would happen to the rate of the forward reaction if the concentration of nitrogen were decreased? The reaction rate would . SubmitHintsMy AnswersGive UpReview Part Part C Which of the following would increase the rate of the reverse reaction? Which of the following would increase the rate of the reverse reaction? increasing the concentration of ammonia decreasing the temperature increasing the concentration of nitrogen SubmitHintsMy AnswersGive UpReview Part Part D What will happen to the rates of the forward and reverse reactions when a catalyst is added? What will happen to the rates of the forward and reverse reactions when a catalyst is added? Forward rate increases; reverse rate decreases. Both forward and reverse rates increase. Both forward and reverse rates decrease. Forward rate decreases; reverse rate increases.

Answer 1

The Haber's process involves the equilibrium reaction

N_2(g) + 3H_2(g) <------> 2NH_3(g) + heat

The reaction is exothermic reaction and proceeds with less number of moles on the product side.

Thus the favorable condistions according to Le Chatlier principle are

i) low temperature

ii) high pressure

iii) increase in concentration of either / both the reactants or decrease in concentration of the product

iv) employing a catalyst

for the forward reaction.

Part A) What happens to the reaction if the temperautre is reduced to 100C.

according to Le Chatlier low temperature favors the forward reaction. However the practical difficulty is , at this temperature , the reaction between hydrogen and nitrogen is not initiated, as the reaction has high activation energy.

Thus the answer is the forward reaction is not favored. The rate of reaction decreases.

Part B)If the concentration of nitrogen( one of the reactants) decreases, the rate of reaction decreases according to Le Chatlier principle.

Part C)

Which of the following increase the rate of reverse reaction?

i) increasing the concentration of ammonia.

When the product concentration is increased, the equilibrium responds in such a way to reduce its concentration, that is the reverese reaction rate increases ther by reactant concentration increases and product concentration decreases.

thus reverse reaction rate is increased.

ii)decreasing the temperature

When the temperature is lowered, the reaction proceeds in such a way to increase it, that is exothermic forward reaction is favored but not reverese reaction.

iii) increasing concentration of nitrogen.

Increase in reactant nitrogen concentration favors forward reaction, as the equilibrium shifts in a way to reduce the concentration of reactant. Thus rate of forward reaction increase, but not reverse.

Part D)

When a catalyst is added, it increases both the forward and reverse reaction rates equally.