Question

Which of the following compounds will react faster?

${CH}_3{CH}_{2}Br$ or ${CH}_3{CH}_{2}I$ with $NaOH$ in ethanol________.

• A. ${CH}_3{CH}_{2}I>{CH}_3{CH}_{2}Br$
• B. ${CH}_3{CH}_{2}I<{CH}_3{CH}_{2}Br$
• C. ${CH}_3{CH}_{2}I={CH}_3{CH}_{2}Br$
• D. None of these

Answer 1

The correct option is A ${CH}_3{CH}_{2}I>{CH}_3{CH}_{2}Br$

Solvents that can donate Hydrogen bonds ($-OH$ or $-NH$)slow $S_{N}2$ reaction by associating with reactants.

Energy is required to break interactions between reactant and solvent.

But there is no need to consider the effect of solvent as larger halide ions are better leaving group.

Iodoalkanes$(R-I)$ react more rapidly than bromoalkanes $(R-Br)$.

Hence, the correct option is A.