Please explain that why the volume of ice is neglected here of ice at 0c and 4-6 mmhg pressure is converted to water vapour at a konstant temperature and

Since pAV is very Siae Thus Thus, AH AU=1440 calories. 6. 1 17ole of ice at 0C and 4-6 mmHg pressure is converted to water vapour at a konstant temperature and pressure. Find AH and AU if the latent heat of latent heat of Phusfon of Tce is 80 cal/g and latent heat of vaporisation of liquid water at OPC uid water at 0°C Is 596 cal/g and the volume of ice in comparison to that of water (vapour) is water (vapour) is neglected