Question

When performing an Sn1 reaction how do I know if acetone will need to be used? Also for Sn2 is there any case where a protic solution will be needed instead of an aprotic?

Answer 1

for Sn1, the attacking group is most often through solvolysis. as for Sn2 it requires an aprotic solvent. However, it's often done in room temperature. Elevating the temperature and using a polar protic solvent will result in a different reaction with different products (E1 reaction). But it also has to do with the bulkyness of the reactant.