Gen. Chem
posted by carl on .
Could you help me with this homework please..
105.0 g of water is in a Styrofoam calorimeter of negligible heat capacity. The initial T of the water is 17.1oC. After 288.2 g of an unknown compound at 77.0oC is added, the equilibrium T is 25.1oC. What is the specific heat of the unknown compound in J/(goC)?

heat lost by unknown compound + heat gained by H2O = 0
[mass unknown x specific heat unk x (TfinalTinitial)] +[mass H2O x specific heat H2O x (TfinalTinitial)] = 0
Substitute and solve for specific heat unknown.