A glass contains 250.0 g of warm water at 78.08C. A piece of gold at 2.308C is

Question:

A glass contains 250.0 g of warm water at 78.08C. A piece of gold at 2.308C is placed in the water. The final temperature reached by this system is 76.98C. What was the mass of gold? The specific heat of water is 4.184 J g^-1 8C21 and that of gold is 0.129 J g^-1 8C^-1.

Strategy We will need to assume that heat flows only between the gold and the water, with no heat lost to or gained from the glass or the surroundings. Then the heats must balance; the heat gained by the gold was lost by the water. Each of those can be calculated using Equation 9.3, and the two must be equal and opposite in sign.

Equation 9.3