29:006 Exercises on Heat Capacity

The heat required to raise the temperature of a mass m of a substance can be calculated from:

Heat = mass  in grams x specific heat in Calories per gram degree C  x temperature change in C

The specific heat of water is 1 Calorie/g C

The formulas can also be used to find the amount of heat that must be removed from a substance to cool it.

Remember that the mass must be in grams!

Ex. 1) How much heat is required to raise the temperature of 2 kg of water from 45 to 55 degrees C?

Ex. 2) How much heat must be removed from 5 kg of water to cool it from 10 to 2 degrees C?

Solutions:

1) Heat = mass x specific heat x temperature change = 2000 g x 1 Cal/g C x 10 C  = 20,000 Cal.

2) Heat =  mass x specific heat x temperature change = 5000 g x 1 Cal/g C x 8 C = 40,000 Cal.