The reaction

\[\mathrm{I}^{-}(a q)+\mathrm{OCl}^{-}(a q) \longrightarrow \mathrm{IO}^{-}(a q)+\mathrm{Cl}^{-}(a q)\]

is believed to occur by the following mechanism:

Write the rate law for this reaction. Since the reaction is in aqueous solution, the effective concentration of water remains constant. Thus the rate of the forward reaction in the first step can be written as

\[\text { Rate }=k\left[\mathrm{H}_{2} \mathrm{O}ight]\left[\mathrm{OCl}^{-}ight]=k_{1}\left[\mathrm{OCl}^{-}ight]\]

OCI + HO I + HOCI 2 HOI + CI- k HOI + OH HOCI + OH HO + IO Fast equilibrium Slow Fast