devarshi-dt-logo

Question:

In SN2 reactions, the correct order of reactivity for the following compounds CH3Cl, CH3CH2Cl, (CH3)2CHCl and (CH3)3CCl is:

CH3CH2Cl>CH3Cl>(CH3)2CHCl>(CH3)3CCl

(CH3)2CHCl>CH3CH2Cl>CH3Cl>(CH3)3CCl

CH3Cl>(CH3)2CHCl>CH3CH2Cl>(CH3)3CCl

CH3Cl>CH3CH2Cl>(CH3)2CHCl>(CH3)3CCl

Solution:

Rate of SN2 reaction ∝ 1/steric overcrowding in transition state
So, the reactivity of CH3Cl will be the most. And as the steric hindrance increases rate of SN2 will decrease. And hindrance increases with crowding on the central atom.
Hence the correct order is option D.