How will the rate of reaction be affected when
(a) surface area of the reactant is increased,
(b) temperature of the reaction is decreased, and
(c ) catalyst is added in a reversible reaction?

Explanation

(a) Surface area of the reactant is increased
When surface area of the reactant is increased, there is greater contact between the reactant molecules. Hence rate of reaction increases.
(b) Temperature of the reaction is decreased
Kinetic energy of the molecules depends upon the temperature. On decreasing the temperature, the kinetic energy of the molecules becomes smaller. There are smaller and less effective collisions between the molecules. This results in decrease in the rate of reaction.
(c ) The equilibrium will be achieved earlier but there will be no change in the equilibrium point.