Question

How many of the following solvent support S$_N$1 reaction? H₂O, ethanol, THF, Diethyl ether, Isopropanol

Answer 1

3

Answer 2

S$_N$1 reactions are favored by polar protic solvents. These solvents stabilize the carbocation intermediate and the leaving group.

1. H₂O: Polar protic. Supports S$_N$1.
2. Ethanol: Polar protic. Supports S$_N$1.
3. THF: Polar aprotic. Does not support S$_N$1.
4. Diethyl ether: Non-polar aprotic. Does not support S$_N$1.
5. Isopropanol: Polar protic. Supports S$_N$1.

Thus, 3 solvents support S$_N$1 reaction.