Question

Consider the reaction of chloromethane with $O{H}^{-}$ in aqueous solution $C{H}_{3}Cl\left(aq\right)+OH\left(aq\right)\underset{K_r}{\stackrel{K_f}{\rightleftharpoons }}C{H}_{3}OH\left(aq\right)+Cl\left(aq\right)$
At ${25}^{o}C$, the rate constant for the forward reaction is $6\times {10}^6{M}^1{s}^{-1}$, and the equilibrium constant $K_c$ is $1\times {10}^{16}$.

Calculate the rate constant for the reverse reaction at ${25}^{o}C$.

• A. $3\times {10}^{22}$
• B. $6\times {10}^{22}$
• C. $12\times {10}^{22}$
• D. $12\times {10}^{23}$

Answer 1

The correct option is B $6\times {10}^{22}$

As we know,

$K_c=k_f/k_b$

$k_b=K_c\ast k_f$

$=1\times {10}^{16}\times 6\times {10}^6$

$=6\times {10}^{22}$