Arrange the leaving groups Cl-, CH3COO-, OH- and NH2- in decreasing order of leaving-group ability.

JEE Main levelSingle correct optionDifficulty 2 of 3o3028

Arrange the leaving groups $Cl X^{-}$ , $CH X_{3} COO X^{-}$ , $OH X^{-}$ and $NH X_{2} X^{-}$ in decreasing order of leaving-group ability.

Leaving ability parallels the acidity of the conjugate acid: HCl (

p K_{a}

about

- 7

CH X_{3} COOH

(4.8),

H X_{2} O

(15.7) and

NH X_{3}

(about 38). The weaker the base, the better the leaving group, giving the order

Cl X^{-} > CH X_{3} COO X^{-} > OH X^{-} > NH X_{2} X^{-}