specific latent heat of vapourization is the amount of heat energy needed to change 1 kg of liquid to vapour without a temperature change. The heat absorbed by the liquid at the beginning of vapourization is 8×103J and heat absorbed after the change of stage is 53×103J. therefore, the total heat energy needed to change the liquid completely to vapour is Q=53×103−8×103J=45×103J Recall, Q=mL Where, L= specific latent heat of vapourization Q=mL L=