Chemistry - Thermodynamics - II Question with Solution | TestHub

Gibbs Free Energy (B): For any phase transition occurring at equilibrium under constant temperature and pressure, the change in Gibbs free energy ($\Delta G_{vap}$) is always zero.

Entropy of Universe (D): An equilibrium phase change is a perfectly reversible thermodynamic process, meaning the total entropy change of the universe ($\Delta S_{univ}$) is zero.

Enthalpy of Vaporization (A): Converting a liquid into a gas requires absorbing heat (endothermic), which means $\Delta H_{vap}>0$ and cannot be zero.

Entropy of System (C): Gas molecules have significantly higher disorder than liquid molecules, meaning the system's entropy change ($\Delta S_{sys}$) is always positive, not zero.