Heat capacity

Heat capacity (C) is defined as the amount of heat needed to raise the temperature of a system by one degree (Celsius or Kelvin), and is expressed in units of Joules per degree Kelvin ([math]\frac{J}{K}[/math]).[1] This is not to be confused with specific heat capacity which is very similar, but also depends on the mass that is being heated.

Heat capacity can be measured with a calorimeter, which is ideally well insulated so that no heat escapes during the experimental process. A thermometer is placed in the calorimeter and the substance inside is heated, and by measuring the temperature change and energy supplied, the value for heat capacity can be derived. The equation that gives the heat capacity (C) is:[2]

[math]C=\frac{Q}{\Delta T}[/math]


  • [math]Q[/math] is the heat supplied
  • [math]\Delta T[/math] is the change in temperature of the substance


  1. UC Davis Chemwiki, Heat Capacity [Online], Available: http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/Calorimetry/Heat_Capacity
  2. Davidson Chemistry, Calorimetry: Heat Capacity [Online], Available: http://www.chm.davidson.edu/vce/calorimetry/heatcapacity.html