At the azeotropic composition, the relative volatility of a binary liquid mixture equals_______________________?
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Answer: A. 1
Explanation
Azeotropic compositions produce identical vapor and liquid phase chemical concentrations. Identical vapor and liquid mole fractions make the relative volatility ratio equal one. Reaching an azeotropic point halts further separation via standard fractional distillation. Azeotropes are liquid mixtures that boil without changing their overall chemical composition. Vapor-liquid equilibrium curves intersect the diagonal line at azeotropic mixture points. Relative volatility is calculated as the ratio of vapor ratios to liquid ratios.
Ethanol-water mixtures form an azeotrope that prevents pure alcohol production via distillation alone. Chemical engineers use extractive distillation to break difficult azeotropic binary mixtures. Understanding azeotropes is crucial for designing safe and effective solvent recovery systems. Relative volatilities greater than one indicate normal binary mixtures that are easily separated. A relative volatility of zero contradicts thermodynamic definitions of vapor-liquid equilibrium. Infinite relative volatility indicates extreme separation ease without azeotropic composition limitations.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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