Question

In a reaction A → B, the rate of reaction increases two times on increasing the concentration of the reactant four times, then order of reaction is:

(a) 0
(b) 2
(c) 1/2
(d) 4

Answer 1

(c) 1/2

(i) r = ka^α, (ii) 2r = k(4a)^α

Dividing (ii) by (i),

4^α = 2 or 2^2α = 2 or 2α = 1 or α = 1/2.