Question

Which one of the following compounds will undergo hydrolysis at a faster rate by S_N1 mechanism? Justify.

Answer 1

The following compound will undergo S_N1 faster:

Greater the stability of the carbocation, greater will be its ease of formation from the corresponding halide and faster will be the rate of reaction. The benzylic carbocation formed gets stabilised through resonance.

CH₃CH₂CH₂Cl forms a 1° carbocation, which is less stable than benzylic carbocation.