The magnitudes of enthalpy changes for irreversible adiabatic expansion of a gas from 1L to 2L is H₁ and for reversible adiabatic expansion for the same expansion is H₂. Then

H U PV For adiabatic process, T f H nR T nR T nC T p 2 Magnitude - wise H Now, the work done by the gas is maximum in reversible adiabatic process (i.e. more than irreversible) Now, i.e. W v w T [Since change in volume is same] Accordingly, W H T