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

`aA to xP`
Rate of reaction `=[A]^(a)`
Order of reaction =a
`[A]_(1)=2.2mM`, `r_(1)=2.4mMs^(-1)` ............(i)
`[A]_(2)=2.2//2mM`, `r_(1)=0.6mMs^(-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`