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), the amount of heat energy (measured in joules) 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 heat 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))
cp: specific heat capacity at constant pressure
Lesser the specific heat capacity, easier is to change the temperature of the substance and vice-versa.
Factors that influence heat capacity measurements
- Temperature: For example, measuring the heat capacity of water produces different results if the starting point is 20 °C rather than 60 °C.
- Intermolecular forces: If a fluid has strong intermolecular forces (such as hydrogen bonding in water) then the heat capacity is likely to be higher.
Table of specific heat capacities
| Substance | Phase | Specific heat capacity J/(kg·K) |
|---|---|---|
| Aluminium | solid | 900 |
| Brass | solid | 377 |
| Copper | solid | 385 |
| Diamond | solid | 502 |
| Ethanol | liquid | 2460 |
| Gold | solid | 129 |
| Graphite | solid | 720 |
| Iron | solid | 444 |
| Lithium | solid | 3582 |
| Mercury | liquid | 139 |
| Oil | liquid | ≈ 2000 |
| Water | liquid | 4186 |
| solid (0 °C) | 2060 | |
| Standard ambient temperature and pressure used unless otherwise noted. | ||
See also
- heat
- heat capacity
- latent heat
- specific melting heat
- specific heat of vaporization
- temperature
- volumetric heat capacity