You are given unknown substance with mass of 138.2 g. The unknown substance is heated to a temperature of 102.1°C, and then dropped into a calorimeter that is at an initial temperature of 22.2°C. The mass of the aluminum inner cup is 35.2 g. The mass of the inner cup plus water is 74.3 g. When equilibrium is established, the temperature is 28.7°C. There are no phase changes. The specific heat of the calorimeter is 0.215 cal/ gram °C . What is the specific heat of the unknown substance?