Question

Given the gas-phase reaction N_2 + 3H_2 = 2NH_3 Suppose that the action has already taken place, and the system has come to equilibrium. If the following changes are made to the system in equilibrium, tell what effect these chants will have on the system (whether the equilibrium is shifted to the left, the right, or is not shifted). a. Additional N_2 is added to the system. b. Ammonia is removed from the system as soon as it forms. c. The pressure of the system is increased (all components are gases). d. A very efficient catalyst is used for the reaction.

Answer 1

The given gas phase reaction is known as Haber process under conditions of temperature , pressure & concentration. It is based on Lechateliers principle. Through this principle we can predict qualitatively the influence of change in temp, pr or concentration on system in equilibrium.

N2 + 3H2 $\rightleftharpoons$ 2NH3

a . When additional N2 is added , the quantity of NH3 has increased , a new equilibrium state is formed & it is shifted to the right.

b . This reaction is reversible reaction & some H2 & N2 remain mixed with the NH3 . The reaction mixture is cooled so that NH3 liquifies & can be removed. So the equilibrium continously shifted to the right.

c . Increasing the pr causes the equilibrium position to move to the right resulting in a higher yield of NH3 since there are more gas molecules on the left than the right.

d . Catalyst affect only the rate of a reaction , they have no effect on the equilibrium state.