The rate of reaction between two `A` and `B` decreases by factor `4` if the concentration of reactant `B` is doubled. The order of this reaction with respect to `B` is

Options

A. -1
B. -2
C. 2
D. 1

Explanation

`r_1=k[A]^m[B]^m, ……(i)`
Also, `r_2=k[A]^m[2B]^n, and r_2/r_1= 1/4…..(ii)`
Dividing (ii) by (i)
`4=(1/2)^n or 2^2=2^(-n) :.n=-2`