According to the Mayer’s relation or the Mayer’s formula the difference between these two heat capacities is equal to the universal gas constant. Cp = Cv + R

## Mayer’s relation – Mayer’s formula

Julius Robert Mayer, a German chemist and physicist, derived a relation between **specific heat at constant** pressure and the **specific heat at constant volume** for an ideal gas. He studied the fact that the specific heat capacity of a gas at constant pressure (C_{p}) is slightly greater than at constant volume (C_{v}). He reasoned that this *C*_{p} is greater than the molar specific heat at constant volume *C*_{v}, because energy must now be supplied **not only** to** raise the temperature** of the gas but also for the **gas to do work** because in this case volume changes. According to the **Mayer’s relation** or the **Mayer’s formula** the difference between these two heat capacities is equal to the universal gas constant, thus the molar specific heat at constant pressure is equal:

**C**_{p} = C_{v} + R

References:

**Reactor Physics and Thermal Hydraulics:**
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