If 150 grams of water is heated from 200°C to 0°C, how many joules of heat energy are absorbed?
We need three pieces of information.
(i) The heat capacity of gaseous water.
(ii) The heat of evaporation (to cope with the phase transition, when the water vapour condenses).
(iii) The heat capacity of liquid water.
(iv) The heat of fusion for ice (to cope with the last phase transition).