The reaction `NH_(4)^(+)+ OCN^(-) rarr OC (NH_(2))_(2)` , proceeds through the following mechanism.
`NH_(4)^(+)+OCN^(-) overset(k_(eq))rarr NH_(4)` OCN (fast)
`NH_(4)OCN overset(k) rarr OC(NH_(2))_(2)` (slow)
The rate constant of the reaction is

Options

A. k
B. `kk_(eq)`
C. `k//k_(eq)`
D. `k_(eq)//k`

Answer

B

Explanation

From slow stem we writer r=k `[NH_(4)OCN]`
rate law is `r=(kk_(eq))[NH_(4)^(+)][OCN^(-)]` The rate constant is `kK_(eq)`