Question

An aluminum cup contains 225 g of water and a 40 g copper stirrer, all at 27°C. A 470 g sample of silver at an initial temperature of 89°C is placed in the water. The stirrer is used to stir the mixture gently until it reaches its final equilibrium temperature of 32°C. Calculate the mass of the aluminum cup.

Answer 1

Using conservation of heat

Heat lost by silver = heat gained by water stirrer and cup

Using

H = mc

where m is the mass

c is the specific heat capacity

is change in temperature

0.470*230*(89-32) = 0.225*4186(32-27) + 0.040*390(32-27) + m*900(32-27)

6161.7 = 4709.25 + 78 + m*4500

m = 305 g