The chemical reaction `2O_(3) overset(k_(1))rarr 3O_(2)` proceeds as follows:
`O_(3) overset(k_(eq))hArr O_(2)+O` (fast)
`O + O_(3) overset(k)rarr 2O_(2)` (slow)
What should be the rate law expresison ?

Options

A. `r=k[O_(3)]^(2)`
B. `r=k[O_(3)]^(2)[O_(2)]^(-1)`
C. `r=k [O_(3)][O_(2)]`
D. unperidictable

Answer

B

Explanation

From equation (i), `K_(eq)=([O][O_(2)])/([O_(3)])`
or `[O]=(K_(eq).[O_(3)])/([O_(2)])`
`"Rate law"=K[O_(3)][O]`
`or r = k([O_(3)][O_(3)])/([O_(2)])K_(eq)`
or `r = k'[O_(3)]^(2)[O_(2)]^(-1)`