10.3 Specific Heat Capacity
The energy required to heat a material depends on three factors:
- Mass of the substance
- Change of temperature
- Nature of the material
Some substances absorb heat more easily than others. For example, heating 1 kg of water by 1 °C requires more energy than heating 1 kg of alcohol by the same amount. This relationship is expressed using the formula:
Q = m c ΔT
where:
- Q = heat energy
- m = mass of the substance
- ΔT = change in temperature
- c = specific heat capacity
Specific heat capacity (c) is the amount of heat energy needed to increase the temperature of 1 kg of a substance by 1 °C (or 1 K). The SI unit of specific heat capacity is J kg⁻¹ K⁻¹.