Calculation Of Vapour-liquid Equilibria.

[irreplaceable]

Hello!
I have a little question. I have ternary system, which consist 2 gas and water. Gases dissociate and is weak electrolytes. How do I to calculate composition of vapour phase which is be in equilibrium with liquid phase, if we know composition of liquid phase, temperature and pressure.
Thanks in advance!
Regards,
Denis.

[Guillermo Culebro Nieves]

You have the liquid compositions, then you must to find
y1+y2+y3=1(vapor phase) AND x1+x2+x3=1(liquid phase), yi=ki*xi, yuo have xi. you must find Ki. a tmperature of equilibrium, the pressure is the total. and comprobe the sum=1. you have the pressure and the euilibrium temperatura,like sum(ki*xi)=1 yuo heve yi in the vapour phase

[Muhammad adnan hanif]

Dear Friend;

Hope you shall be in good health and enjoying the summer season. In my opinion, simple method is first get the partial pressure of each component by following method;

- As you know; total pressure of the system, temperature and composition of each component in liquid phase. Therefore, first of all get vapor pressure data of each component at the operating temperature (system temperature) from literature i.e engineering data books like chemical engineers hand book written by perry .

- Calculate partial pressure of each component in vapor face as given below;

Partial pressure of a component = (Vapor pressure of a component) * (Composition of that component in liquid phase)

Remember: Addition of all three components partial pressure will be equal to the total pressure of the system.

- Get composition of each component in vapor phase by following formula;

Vapor composition of a component in % age = {(Partial pressure of a component) / (Total pressure of the system)} * 100

I hope this may resolve the issue.

Note: YOu may also utilize equilibrium constants factor method. For that you have to search out that factors for each component at the operating temperature and pressure from literature.

Take care and have a nice life.

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