The specific latent heat of vaporisation, L of a substance is the heat quantity required to convert one unit mass of a liquid into water vapour at its boiling limit without any change in temperature.
Its unit is JKg-1.
If m Kg of liquid or water vapour is involved, the quantity of heat, Q absorbed or released is
Q = ml
Q = quantity of heat that is absorbed or released.
m = mass of the substance
l = specific latent heat of vaporization
The list below show the specific latent heat of vaporization for a few substances
Methylated spirit - 1.12 X 10^3
Ether - 3.70 X 10^2
Mercury - 2.72 X 10^2
Water - 2.26 X 10^6
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