Question

Why is ethanol not used in SN2 reactions?

Answer 1

Ethanol is a polar protic solvent.

Explanation:

`S_N2` reactions "favor" certain conditions, just like `S_N1, E_1,`and `E_2` reactions.

Favorable conditions for bimolecular nucleophilic substitution reactions include polar aprotic solvents. Polar protic solvents hinder `S_N2` reactions, as they can hydrogen bond to nucleophiles and make them less effective in attacking the substrate. Ethanol is a polar protic solvent (though alcohols are only weakly acidic). It is commonly seen as a solvent/nucleophile (solvolysis) in `S_N1` reactions.