Question

Which reaction in each of the following pairs would you expect to be faster?

(a) The$S_{N}2$displacement by$I^{-}onC{H}_{3}ClorC{H}_{3}OTs$

Short answer

$C{H}_{3}OTs$$showsfastreactionthan$$C{H}_{3}Cl$

Step-by-step solution

SN2reaction

It is a nucleophilic substitution reaction in which an old bond is broken and a new bond is formed both processes occur simultaneously. Hence, it’s a single-step reaction.

The two reacting species are involved in the rate-determining steps.

Nucleophile

Nucleophiles are the negatively charged ions or the neutral species having the lone pair of electrons that are ready for bonding.

Species react faster I-

If the species areis a better leaving group then it reacts faster with the nucleophile$C{H}_{3}OTs$

is a better leaving group than $C{H}_{3}Cl$

$C{H}_{3}OTs$$is\text{\hspace{0.33em}}showfastreactionthan$$C{H}_{3}Cl$