I realise that there has been a post recently concerning this sort of thing but i think it went a bit off topic for me to follow. :) The question is Consider a bowl containing 1 mol of ice at a temperature of -10C and atmospheric pressure. The sample is heated very slowly to 115C. Split the process into five characteristic phases. How much heat is consumed and work done during each of the phases? What changes occur in internal energy and in the Gibbs function during the entire process? All specific heats are given and latent heats aswell as being told to neglect entropy changes apart from during phase transition. I know the five stages Ice (-10) - Ice (0) - Water (0) etc. and i can work out the amount of heat at each stage using the (mass) . (specific heat) . (Change in temp), and (mass) x (latent heat) for the constant temp. stages. What i dont understand is working out the work done during each phase. I think i need to use U = Q - W and then calculate U and then hence forth calculate W but im not sure if this is right or even how to do it. Thanks for any help.