Project ForgeProcess Calculations
Laws of Thermodynamics
GATE 2014
Medium
From the following list, identify the properties which are equal in both vapour and liquid phases at equilibrium: P. Density, Q. Temperature, R. Chemical potential, S. Enthalpy
- AP and Q only
- Q and R only
- CR and S only
- DP and S only
Explanation
Phase equilibrium requires thermal equilibrium (equal temperature, T) and equal chemical potential of each species in both phases (the defining condition of phase/chemical equilibrium). Density and enthalpy per unit mass are generally very different between the vapour and liquid phases (that difference is the latent heat and density change of vaporization).
Source: GATE CH 2014 (2014)
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