The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition.

A. Internal energy

B. Enthalpy

C. Gibbs free energy

D. Helmholtz free energy

Answer: Option C

Solution(By Examveda Team)

Gibbs free energy:
$$\eqalign{ & G = H - TS \cr & \Rightarrow - dG = {W_R} - PdV \cr} $$
So, the decrease in Gibbs energy represents maximum useful work (excluding the expansion work) in a reversible process under isothermal and isobaric conditions.