Question

Tertiary alkyl halides are partially inert to substitution by S_N2 mechanism because of

(a) insolubility

(b) instability 

(c) inductive effect

(d) steric hindrance

Answer 1

Answer is : (d) steric hindrance

Tertiary alkyl halides are partially inert to substitution by S_N2 mechanism because of steric hindrance. In S_N2 reaction, nucleophile and alkyl halide reacts in one step.

The transition state is involved which is more stable in case of unhindered carbons.