Question

Which compound in each of the following pairs will react faster in S_N2 reaction with OH^-?
i. CH₃Br or CH₃I
ii. (CH₃)CCl or CH₃C

Answer 1

i. Since Γ  ion is a better leaving group than Br^- ion, therefore, CH3I reacts faster than CH₃Br in SN₂ reaction with OH^- ion.

ii. On steric grounds, 1⁰ alkyl halides are more reactive than tert-alkyl halides in S_N2 reactions.Therefore, CH₃Cl will react at a faster rate than (CH₃)₃CCl in an S_N2 S reaction with OH^- ion.