JEE Main2017ChemistryHaloalkanes and HaloarenesActual
The increasing order of the reactivity of the following halides for the S N 1 reaction is
Options
- A( II ) < ( I ) < ( III )
- B( I ) < ( III ) < ( II )
- C( II ) < ( III ) < ( I )
- D( III ) < ( II ) < ( I )
Correct answer
A. ( II ) < ( I ) < ( III )
Step-by-step solution
Rate of S N 1 reaction is directly dependent on the stability of carbocation intermediate. (II) is primary alkyl halide. (I) is secondary alkyl halide. Primary alkyl halide is less reactive towards S N 1 reaction than secondary alkyl halide. In (III), the carbocation generated is stabilised due to resonance. Hence, (III) is most reactive towards S N 1 reaction.