Specific Heat Capacity in Chemistry

Specific Heat Capacity Definition

Specific heat capacity is the amount of heat energy required to raise the temperature of a substance per unit of mass. The specific heat capacity of a material is a physical property. It is also an example of an extensive property since its value is proportional to the size of the system being examined.

In ​SI units, specific heat capacity (symbol: c) is the amount of heat in joules required to raise 1 gram of a substance 1 Kelvin. It may also be expressed as J/kg·K. Specific heat capacity may be reported in the units of calories per gram degree Celsius, too. Related values are molar heat capacity, expressed in J/mol·K, and volumetric heat capacity, given in J/m³·K.

Heat capacity is defined as the ratio of the amount of energy transferred to a material and the change in temperature that is produced:

C = Q / ΔT

where C is heat capacity, Q is energy (usually expressed in joules), and ΔT is the change in temperature (usually in degrees Celsius or in Kelvin). Alternatively, the equation may be written:

Q = CmΔT

Specific heat and heat capacity are related by mass:

C = m * S

Where C is heat capacity, m is mass of a material, and S is specific heat. Note that since specific heat is per unit mass, its value does not change, no matter the size of the sample. So, the specific heat of a gallon of water is the same as the specific heat of a drop of water.

It's important to note the relationship between added heat, specific heat, mass, and temperature change does not apply during a phase change. The reason for this is because heat that is added or removed in a phase change does not alter the temperature.

Also Known As: specific heat, mass specific heat, thermal capacity

Specific Heat Capacity Examples

Water has a specific heat capacity of 4.18 J (or 1 calorie/gram °C). This is a much higher value than that of most other substances, which makes water exceptionally good at regulating temperature. In contrast, copper has a specific heat capacity of 0.39 J.

Table of Common Specific Heats and Heat Capacities

This chart of specific heat and heat capacity values should help you get a better sense of the types of materials that readily conduct heat versus those which do not. As you might expect, metals have relatively low specific heats.

Sources

• Halliday, David; Resnick, Robert (2013). Fundamentals of Physics. Wiley. p. 524.
• Kittel, Charles (2005). Introduction to Solid State Physics (8th Ed.). Hoboken, New Jersey, USA: John Wiley & Sons. p. 141. ISBN 0-471-41526-X.
• Laider, Keith J. (1993). The World of Physical Chemistry. Oxford University Press. ISBN 0-19-855919-4.
• unus A. Cengel and Michael A. Boles (2010). Thermodynamics: An Engineering Approach (7th Edition). McGraw-Hill. ISBN 007-352932-X.