Sn1 and Sn2 mechanisms?

great ans.

Sn1 reaction occur in two steps .first is the formation of carbocation then attack by nucleophile to give the desired product.sn1 reaction also known as solvolysis because here solvent act as a nucleophile .it is favoured by polar protic solvent like water alcohol.f ollow first order kinetics.rate of reaction depend only on the concentration of alkyl halide .rate of sn 1 reaction is directly proportional to stability of carbocatio.sn 1 reaction is not possible for three membered ring because carbocation is sp2 hybridized which is planar and in three membered ring angle is 60 it become higly unstable does not favour sn1 reaction.in bridgeded compound also does not favour sn1 reaction due to non planarity .rate of sn1 reaction directly proportional to good leaving grouo .good leaving group means weak conjugate base .for sn1 reaction weak nucleophile is required .