In order to cool 1 ton of water at 20°c in an insulated tank, a person pours 140 kg of ice at –5°c into the water. the specific heat of water at room temperature is c = 4.18 kj/kg· °c, and the specific heat of ice at about 0°c is c = 2.11 kj/kg°c. the melting temperature and the heat of fusion of ice at 1 atm are 0°c and 333.7 kj/kg.