Lesson #06 Importance of equilibrium constant

Importance of equilibrium constant:

Equilibrium constant for a reaction can be used to predict many important features of a chemical reaction.

It can be used for:

a. Determine the equilibrium concentration of equilibrium mixture knowing the initial concentration of reactant.
b. Predict the direction of a chemical reaction.
c. Predict the extent of a chemical reaction.
d. Predict the effect of change in conditions of the chemical reaction on the equilibrium state.

Example:

Ammonia is produced by the reaction of nitrogen with oxygen at 450℃,200 atm pressure in the presence of catalyst.

Reaction:

N20 + 3 H20 → 2 N-IIIH3I

This is an oxidation-reduction (redox) reaction:

6 H0 - 6 e- → 6 HI
(oxidation)

2 N0 + 6 e- → 2 N-III
(reduction)

Explanation:

This is known as haber process. This is a reversible process and produces only 33% NH3 at equilibrium. The high pressure is used to favour the formation of ammonia. Then,cooling the equilibrium mixture gives 98% ammonia.