Specific heat capacity

The specific heat capacity (symbol c or s, also called specific heat) of a substance is defined as heat capacity per unit mass. The SI unit for specific heat capacity is the joule per kilogram kelvin, J·kg^-1·K^-1 or J/(kg·K), which is the amount of energy required to raise the temperature of one kilogram of the substance by one kelvin. Heat capacity can be measured by using calorimetry.

The equivalent definition using cgs units is the amount of energy (measured in ergs) required to raise the temperature of one gram of the substance by one degree Celsius (erg/(g·°C)). Other units of specific heat capacity include calories per gram degree Celsius (cal/(g·°C) or cal/(g·K)) and Btu per pound degree Fahrenheit (Btu/(lb·°F))

The symbol c_p is often used to denote specific heat capacity at constant pressure.

Substances with low specific heat such as metals require less input energy to increase their temperature. Substances with high specific heat such as water require much more energy to increase their temperature. The specific heat can also be interpreted as a measure of how well a substance preserves its temperature, i.e. "stores" heat, hence the term "heat capacity".

Factors that influence heat capacity measurements

• Temperature: Measuring the heat capacity of water produces different results if the starting point is 20 °C rather than 60 °C. Therefore the temperature the measurement was conducted at must be specified for the value to be useful.
• Intermolecular forces: Strong intermolecular forces (such as hydrogen bonding in water) are likely to increase the heat capacity of a substance.

Table of specific heat capacities

See also

• heat
• heat capacity
• heat transfer coefficient
• latent heat
• specific melting heat
• specific heat of vaporization
• temperature
• volumetric heat capacity