Conisder a reaction `aG+bH rarr` Products. When concentration of both the reactants `G` and `H` is doubled, the rate increases eight times. However, when the concentration of `G` is doubled, keeping the concentration of `H` fixed, the rate is doubled. The overall order of reaction is

Options

A. 0
B. 1
C. 2
D. 3

Answer

D

Explanation

`aG+bHrarr`products
The rate law is
`Rate_(1)=k[G]^(x)[H]^(y)`
Rate^(2)=k[2G]^(x)[2H]^(y)`
Dividing rate by we get
(Rate_(2))/(Rate_(1))=(8Rate_(1))/(Rate_(1))=(k[2g]^(x)[2H]^(y))/(k[G]^(x)[H]^(y))`
`8=2^(x).2^(y)`
`2^(3)2^(x+y)`
:. Overall order is `3` .
We need second information only if we asked about individual orders.