For reaction `aArarrxP` when [A] =2.2 m M, the rate was found to be 2.4 m `M s^(-1)` . On reducing concentration of A to half, rate changes to `0.06 m M s^(-1)` . The order of reaction with respect to A is :

Options

A. 1.5
B. `2.0`
C. `2.5`
D. `3.0`

Answer

b

Explanation

`a A to x`P
Rate of constant = `[A]^(a)`
Order of reaction = a
`[A]_(1) = 2.2` mM , `r_(1) = 2.4 m M s^(-1) " " … (i)`
`[A]_(2) = 2.2//2 m M , r_(1) = 0.6 m M s^(-1)` or `(2.4)/(4) " " … (ii)`
On reducing the concentration of A to half , the rate of reaction is decreased by four times .
Rate of reaction = `[A]^(2)`
Order of reaction = 2 .