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? a. divided by 4
b. halved
c. no effect
d. increased 2x
e. increased 3x
f. increased 6x
g. increased 9x

no effect

Explanation:

In an SN2 reaction, the mechanism is bi-molecular and first order in both the alkyl halide and the nucleophile.

Hence the rate of reaction is;

Rate = k [1-iodo-2-methylbutane] [cyanide ion]

Given that it is a bimolecular reaction, if we double the concentration of 1-iodo-2-methylbutane and the concentration of the cyanide ion is halved, the rate of reaction remains the same.