The specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of one mole of that substance by 1 degree Celsius, or 1 Kelvin. It is denoted by C.

Hence, , … (i) where

C = specific heat capacity

Q = heat required to raise the temperature by dT

m = molar mass

dT = change in temperature.

For an adiabatic process, Q = 0. Substituting this value in (i), we get

C = 0.

Hence, for a process at a constant temperature, the specific heat capacity is zero.