In which phase SN2 reactions are favored?

Explanation

SN1 reactions are favoured in polar protic solvent i.e.,the solvents that can form hydrogen bonds.This is because the large dipole moment of the solvent molecule helps stabilise the carbocation formed in the transition state. However polar aprotic solvents are used in SN2 reactions which are polar enough to dissolve the salt containing nucleophile but don't interact strongly with the anion/nucleophile and hence doesn't hinder its activity. In gaseous state molecules are far away from each other with weak intermolecular forces hence the gas molecules will not interact and hinder the activity of the nucleophile in SN2 reactions while the molecules in liquid solvent will be closer to the nucleophile and they might surround the nucleophile molecule lowering the rate of reaction as the rate depends on attack of nucleophile. Rate of SN2 is inversely proportional to the steric hindrance.