Suppose a piece of iron with a mass of 21.5 g at a temp of 100.0 °C is dropped into an insulated container of water.

Question

The mass of the water is 132.0 g and its temperature before adding the iron is 20.0°C. What will be the final temp of the system? Specific heat of iron is 0.46 J/goC.

Answer 1

heat lost by iron = heat gained by water (conservation of energy)

heat lost by iron = q = mC∆T = (21.5 g)(0.46 J/gº)(100º - Tf) where Tf is final temperature

heat gained by water = q = mC∆T = (132 g)(4.184 J/gº)(Tf - 20)

(21.5 g)(0.46 J/gº)(100º - Tf) = (132 g)(4.184 J/gº)(Tf - 20)

989 - 9.89Tf = 552Tf - 11046

562Tf = 12,035

Tf = 21.4º