posted by joan .
A 20 g sample of aluminum at 85 degree is dropped in 500g of water. The resulting temperature of aluminum and water is 25 degree. What is the initial temperature of water?
Set the heat lost by aluminum equal to the heat gained by water, and solve for the initial water temperture To (the only unknown). You will need the specific heat of aluminum, C(al).
20 (85 - 25) *C(al) = (25-To)*C(water)*500