Question

Rate of the reaction is fastest when $Z$ is:

• A. $-Cl$
• B. $-N{H}_2$
• C. $-O{C}_2{H}_5$
• D. $-OCOC{H}_3$

Answer 1

The correct option is A $-Cl$

$C{l}^{-}$ is the best leaving group being the weakest nucleophile out of $N{H}_2^{-},C{l}^{-},O{C}_2{H}_5$ and $C{H}_{3}CO{O}^{-}$.

So, when $Z$ is $C{l}^{-}$, the ion leaves faster thus making the reaction the fastest when $Z$ is $C{l}^{-}$.