Question

Which one of the following group has maximum leaving ability for nucleophilic substitution reaction:

• A. $O{H}^{⊝}$
• B. $I^{⊝}$
• C. $C{l}^{⊝}$
• D. $F_{3}CS{O}_3^{⊝}$

Answer 1

The correct option is D $F_{3}CS{O}_3^{⊝}$

Leaving group ability $\propto$ Stability of anion.
Therefore, the most stable anion will leave first. As $F_{3}CS{O}_3^{-}$ is the most stable anion, it is the best leaving group among all.