Specific heat capacity is the slope (
derivative) of the internal
energy due to random motion of
atoms in a sample as a function of
temperature, normalized by dividing by the
mass of the sample. Because the internal energy curve is normally almost linear, it can by approximated by measuring the
heat required to raise the
temperature of 1
kg of a substance by 1°
C (or one
Kelvin). The
SI units of measurement for this are J·kg
-1·K
-1.
Factors that influence heat capacity measurements:
- The temperature of the substance. For example, measuring the heat capacity of water produces different results if you start at 20°C, or 60°C.
- Inter-molecular forces. If a fluid has stronger intermolecular forces (such as hydrogen bonding in water) then the heat capacity is likely to be higher.
Heat capacity can be measured using calorimetry
See also: Temperature (heat capacity),
Volumetric heat capacity