Question

To a sample of water at 23.4oC in a constant pressure calorimeter of negligible heat capacity is added a 12.1 g piece of aluminium whose temperature is 81.7oC. If the final temperature of water is 24.9 oC, calculate the mass of the water in the calorimeter.

Answer 1

we use heat balance to answer the following problem. The heat absorbed by water is equal to the heat released by alumimum object. The heat capacity of aluminum is 0.92 J/g C and of water is  4.186 J/g °C. The heat balance is as follows:
mass water * 4.186 J/g C * (24.9 - 23.4 ) C = 12.1 g * 0.92 J / g C * (81.7 - 24. 9) C mass water = 100. 70 grams