Question

Which one is most reactive towards SN1 reaction ?
(a) C₆H₅CH(C₆H₅)Br
(b) C₆H₅CH(CH₃)Br
(c) C₆H₅C(CH₃)(C₆H₅)Br
(d) C₆H₅CH₂Br

Answer 1

Explanation:

option a is the right answer

Answer 2

C₆H₅C(CH₃)(C₆H₅)Br is most reactive towards SN1 reaction

Explanation:

SN1 reaction is unimolecular nucleophilic substitution reaction. It consist of two steps.

In first step ionization of alkyl halide take place. In this step carbocation is formed as an intermediate.

In second step nucleophile attack on carbocation and product is formed.

The first step is slow step because it involve the breaking of covalent bond. While the second step is faster. The first step is called rate determining step.

     Rate = k [ alkyl halide]

The tertiary alkyl halides under goes the SN1 mechanism while primary follow the SN2 and secondary alkyl halides follow both SN1 and  SN2 mechanism.

So option c is correct.