A solid substance with a mass of 200g is at its melting temperature in a calorimeter. While the substance changes from a solid to a liquid at the same temperature, the 400-gram mass of water in the calorimeter goes from an initial temperature of 80 degrees Celcius to a final temperature of 30 degrees Celcius. A. How much heat did the water lose while the substance melted? B. What is the heat of fusion of the substance that melted?