Question

A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is

(i) doubled (ii) reduced to half?

Answer 1

Let the concentration of the reactant be [A] = a

Rate of reaction, R = k [A]²

= ka²

(i)If the concentration of the reactant is doubled, i.e. [A] = 2a, then the rate of the reaction would be

= 4ka²

= 4 R

Therefore, the rate of the reaction would increase by 4 times.

(ii) If the concentration of the reactant is reduced to half, i.e. , then the rate of the reaction would be

Therefore, the rate of the reaction would be reduced to