o Molar enthalpy of vapourisation of a liquid is the amount of heat required to change the state of 1 mole of the liquid to gas.

o Acetone does not consist of any hydrogen bond-like water and that is why intermolecular attractive forces in acetone molecules will be less than that of water molecules which makes it boil (evaporation also)faster.

o On the other hand, water having strong hydrogen bonds and the high polarity also adds up in resulting it to boil at higher temperatures. Hence water has a higher molar enthalpy than acetone.