Question

$ S_N2$ mechanism is involved in the following substitution

• A. $CH_3 - CH_2 - Cl + OH^-$
• B. $CH_3 - \underset{\overset{|}{C}H_3}{\overset{\underset{|}{C}l}{C}}-CH_3 + OH^-$
• C. $ CH_3 - \overset{\underset{|}{C}l}{C}H - CH_3 + OH^-$
• D. $CH_3 - CH_2 - \underset{\overset{|}{C}H_3}{\overset{\underset{|}{C}l}{C}}-CH_3 + OH^-$

Answer 1

Answer: (A)

$S _{ N } 2$ mechanism means bimolecular nucleophilic substitution mechanism. In this, rate of reaction is determined by concentration of two molecules. It is characteristic of $1^{\circ}$ alkyl halides.
(a) $CH_3 - \underset{1^{\circ}\text{alkyl halide}}{CH_2- Cl }+ OH^-$
(b) $\underset{3^{\circ}\text{alkyl halide}}{CH_3 - \underset{\overset{|}{C}H_3}{\overset{\underset{|}{C}l}{C}}- CH_3} + OH$
(c) $\underset{2^{\circ}\text{alkyl halide}}{CH_3 - \underset{\overset{|}{C}l}{C}H - CH_3} 6 OH^-$
(d) $CH_3 - \underset{3^{\circ}\text{alkyl halide}}{CH_2 - \underset{\overset{|}{C}H_3}{\overset{\underset{|}{C}l}{C}} - CH_3} + OH^-$