Question

Which of the following solvent will give maximum yield for an alkyl halide undergoing $S_{N}1$ mechanism over $S_{N}2$?

• A. Water
• B. Ethanol
• C. Diethyl ether
• D. n-hexane

Answer 1

The correct option is A Water

The $S_{N}1$ path is strongly favoured by the presence of polarising solvents which stabilizes both cation and anion effectively. Thus, polar protic solvents favour $S_{N}1$ reaction whereas polar aprotic solvent favours $S_{N}2$ reaction.

Here, only water and ethanol are polar protic solvents.

More polar is a solvent, easier is $S_{N}1$ path. The polarity of the given solvents is water > ethanol > ethoxyethane > n-hexane.

Option A is correct.