An aluminum calorimeter with a mass of 100 g contains 250 g of water. The calorimeter and water are in thermal equilibrium at 10°C. Two metallic blocks are placed into the water. One is a 50.0 g piece of copper at 60.0°C; the other block has a mass of 70 g and is originally at a temperature of 100°C. The entire system stabilizes at a final temperature of 20°C.
a) Determine the specific heat of the unknown sample.
b) Determine a possible substance for the unknown material.