A small amount of water and its saturated vapour are en- closed in a vessel at a

Question:

A small amount of water and its saturated vapour are en- closed in a vessel at a temperature t = 100 °C. How much (in per cent) will the mass of the saturated vapour increase if the temperature of the system goes up by ΔT = 1.5 K? Assume that the vapour is an ideal gas and the specific volume of water is negligible as compared to that of vapour.