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. 2
B. `-1`
C. 1
D. `-2`

Answer

D

Explanation

(i) `r=k[A]^(alpha)[B]^(beta)=ka^(alpha)b^(beta)`
If tthe concentration of B is doubled/
(ii) `r//4 = k^(alpha)(2b)^(beta)`
Dividing 2nd eqn. by 1st eqn.
`1//4=2^(beta)or 2^(beta)=2^(-2)` Hence `beta=-2`.