I'm going to post one or a few questions from a recent chemistry test on which the professor has offered extra credit if we correct the entire test. He has given us the answers to the questions but not the solutions. I have been working on the following question in particular with a few friends for almost two hours and we just can't seem to get the right answer but always very close. The answer is 35.6 deg. C. 1. The problem statement, all variables and given/known data An ice cube at 0 degrees C weighing 9.0 g is dropped into an insulated vessel containging 72 g of water at 50 degrees C. What is the final temperature of the water after the ice has melted and a constant temperature has been reacher? The latent heat of fusion of ice is 6.01 kJ/mol, the molar heat capacity of water is 75.4 J/mol K. 2. Relevant equations nC[tex]\Delta[/tex]T = -nC[tex]\Delta[/tex]T mC[tex]\Delta[/tex]T = -mC[tex]\Delta[/tex]T 3. The attempt at a solution Like I said, we have tried many different approaches but the basic reasoning behind all of them is that whatever heat the ice gains has to be lost by the water, but the once the system reaches equilibrium, the amount of heat lost will equal the amount of heat gained. I guess the main question is when to use the latent heat of fusion or if at all. Any help is greatly appreciated. Thanks.