The specific heat of water is 4200 J kg-1 ° C-1 or 1 cal g-1 C-1, which high compared with most other substances.
Gases have two types of specific heat 1. The specific heat capacity at constant volume( Cv). 2. The specific heat capacity at constant pressure( Cr).
Specific heat at constant pressure( Cp) is greater than specific heat constant volume( CV), i. e., Cp > CV.
For molar specific heats Cp – CV = R where R = gas constant and this relation is called Mayer’ s formula.
The ratio of two principal sepecific heats of a gas is represented by γ.
The value of y depends on atomicity of the gas.
Amount of heat energy required to change the temperature of any substance is given by
Q = mcΔt where, m = mass of the substance, c = specific heat of the substance and Δt = change in temperature. Thermal( Heat) Capacity
Heat capacity of any body is equal to the amount of heat energy required to increase its temperature through 1 ° C.
Heat capacity = me
where c = specific heat of the substance of the body and m = mass of the body.
Its SI unit is joule / kelvin( J / K).