The equation that relates component fugacities in a solution to one another and to concentration at constant temperature and pressure is known as the _____________ equation?
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Answer: A. Gibbs-Duhem
Explanation
The Gibbs-Duhem equation links component chemical potentials together in a multi-component solution. It requires both temperature and pressure to remain strictly constant during the system analysis. This mathematical relationship is fundamental for describing thermodynamic properties of liquid mixtures accurately. Josiah Willard Gibbs and Pierre Duhem independently formulated this important fundamental thermodynamic equation. It represents a constraint among the intensive properties of various components in a mixture. The general formula involves summation of mole fractions multiplied by differential chemical potential changes.
Chemical engineers use this equation extensively when calculating vapor-liquid equilibria for distillation columns. It ensures thermodynamic consistency of experimental activity coefficient models used in design software. Reliable phase equilibrium data prevents costly errors in large-scale chemical plant operations. The Van Laar equation is an empirical model used for predicting excess Gibbs free energy. The Gibbs-Helmholtz equation relates enthalpy changes to temperature variations of Gibbs free energy. The Margules equation describes non-ideal liquid mixture behavior through polynomial expansion coefficients.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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