Question

Which one in the following groups will give a faster reaction in SN2 reaction with OH- ?

(i) CH3Br or CH3I

Answer 1

in SN2 mechanism, the order in which the halides react to some alkyl group is constant. This is because the halide ion becomes a better leaving group when the size of the ion increases.

R-F << R-Cl << R-Br < R-I

Hence, the reactivity of CH3I is faster as compared to CH3Br in SN2 reactions with OH–

Answer 2

HEY:-)

SN² Rxn→

CH3I will react faster than CH3Br because the order of reactivity is as follows:

    R-I > R-Br > R-Cl > R-F