【Q&A】May 7, 2017
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This post was last edited by LQ198619 on 2017-5-7 19:04. Question: What does relative volatility mean? Answer: The value of the relative volatility (α) indicates the ease with which two components can be separated by a separation method. When α=1, the relative equilibrium constants of the two components are equal, meaning that these two components cannot be separated by distillation. When α > 1, the proportion of light components in the gas phase is greater than that in the liquid phase; this is the basis for separating substances with different boiling points using distillation. The larger the value of α, the easier it is to separate them by distillation. The α value changes with variations in temperature and pressure; when these parameters remain relatively constant, α can be approximated as a constant. For hydrocarbons, α decreases as temperature rises and pressure increases, which makes separation difficult during distillation operations at high pressures. http://bbs.hcbbs.com/static/image/hrline/4.gif HaiChuan Network’s special May Day event titled “Remembering the Glorious Moments” http://bbs.hcbbs.com/thread-1774529-1-1.html (Source: HaiChuan Chemical Forum) 【HaiXin Chemical Cup ★ Spring Has Arrived at HaiChuan Chemical】Compilation of posts featuring beautiful scenery from 2017 (you can take a look at the local landscapes posted by users from various places in your free time) http://bbs.hcbbs.com/thread-1766484-1-1.html
It is the ratio of the volatilities of the mutually soluble components in a solution, and can be used as an indicator of the ease with which a liquid mixture can be fractionated.
It indicates that the molar fraction ratio of the two components in the gas phase is α times the molar fraction ratio of the two components in the liquid phase in equilibrium with it.
The relative volatility ratio (α) is the ratio of the volatilities of two components; it indicates the ease with which these two components can be separated by distillation. When α=1, the volatilities of the two components are equal, meaning that they cannot be separated using conventional distillation methods. When α is greater than 1, and the higher this value is, the easier it is to separate the two components by distillation. The α value changes with variations in temperature and pressure; when these parameters remain relatively constant, α can be approximated as a constant. For hydrocarbons, the α value decreases as temperature rises and pressure increases; therefore, distillation under high pressure makes separation difficult.
The ratio of the volatility of the volatile components to that of the non-volatile components also represents the fact that the concentration ratio of these components in the gas phase is a multiple of their concentration ratio in the liquid phase
It reflects the ease of separating these two components using distillation
Under the same temperature and pressure, the ease with which each component evaporates indicates the difficulty of separating the mixed liquid
It indicates that the molar fraction ratio of the two components in the gas phase is α times the molar fraction ratio of the two components in the liquid phase in equilibrium with it.
Relative volatility (α) is the ratio of the volatilities of two components; it indicates the ease with which these two components can be separated by distillation. When α = 1, the volatilities of the two components are equal, meaning that they cannot be separated using conventional distillation methods. When α is greater than 1, and the higher this value, the easier it is to separate the two components via distillation. The value of α changes with temperature and pressure; when these conditions remain relatively constant, α can be considered approximately constant. For hydrocarbons, α decreases as temperature rises and pressure increases, which makes separation difficult under high pressure.
The difficulty of separating two components
The ratio of the volatility of the volatile components in the solution to the volatility of the non-volatile components