Azeotropy of multiple substances
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There are three substances: the first one has a boiling point of 67°C, the second one has a boiling point of 100°C, and the third one has a boiling point of 118°C. If these three substances are mixed to form an azeotrope, under the same conditions, which of the second and third substances will be present in larger amounts? Can it be determined based on their respective boiling points?
Azeotropes have an azeotrope composition, which is not determined by the boiling point; one can look up relevant information. If there is no available data, conducting an experiment is the best approach.
It makes no sense to rely on boiling point for making judgments. On one hand, the azeotrope temperature and composition can be calculated based on phase equilibrium; on the other hand, relevant data can be found in literature. If that’s not possible, experiments are the only option left.
Are you referring to cyclohexane in water-toluene? There are several types of azeotropes, and their azeotopic points can be higher than their respective boiling points, lower than them, or somewhere in between. It’s a value that is determined through measurement. I’m not aware of any theory that can be used to derive this, but there is a book titled Chemical and Physical Handbook that you can consult. Could someone knowledgeable suggest any theory that can be used to determine the tendency for compounds to form azeotropes? Or perhaps a way to classify them?
The contents of each component in the azeotrope are directly related to those in the gas phase; it is necessary to consider the entire system and use phase equilibrium calculations
There are only two types of azeotropes: minimum azeotropes or maximum azeotropes. The most accurate way is to consult literature; if no such literature is available, experiments can be conducted, and when experimental conditions are not feasible, software simulations can be used. I can’t think of any other ways.
What was mentioned upstairs refers to methyl acetate, water, and methanol, right? The azeotemp of these three substances should be calculated based on gas-phase equilibrium, and this can be tested in production through the operation of a distillation tower