Answer to Question #136980 in Organic Chemistry for Muqadas cheema

Question

Primary alkyl halids show E-2 and SN2 reactions not E-1 and SN1 reaction. Why?

Answer 1

The “big barrier” to the SN2 reaction is steric hindrance. The rate of SN2 reactions goes primary > secondary > tertiary. The “big barrier” to the SN1 and E1 reactions is carbocation stability. The E2 reaction has no “big barrier”, per se (although later we will have to worry about the stereochemistry)

In case of primary halide carbocation is not very much stable So , SN1 AND E1 Is not possible but SN2 and E2 go Through Transition State .