Question

What change would you expect on the rate of the SN2 reaction of 1-iodo-2-methylbutane with cyanide ion if the nucleophile concentration is halved and the alkyl halide concentration is doubled

Answer 1

The rate of reaction remains the same, no change is observed

Step-by-step explanation:

Remember that for an SN2 reaction, the rate of reaction depends both on the concentration of the alkyl halide and the concentration of the nucleophile.

Hence we can write; Rate = k [Alkyl halide][NaI]

This implies that if we half the concentration of the nucleophile and double the concentration of the alkyl halide, the rate of reaction just remains the same since the reaction is bimolecular and first order in both alkyl halide and nucleophile