Specific Heat at Constant Pressure (Cp):
It is also defined as the rate of change of specific enthalpy with respect to temperature when pressure is held constant.
Specific Heat at Constant Volume (Cv):
It is also defined as the rate of change of specific internal energy with respect to temperature when volume is held constant.
Relation between CP And CV:
γ = A constant
Why do gases have two value of specific heat while solids and liquids have only one ?