Problem: At 63.5oC the vapor pressure of H2O is 175 torr, and that of ethanol (C2H5OH) is 400 torr. A solution is made by mixing equal masses of H2O and C2H5OH.What is the mole fraction of ethanol in the vapor above the solution?

FREE Expert Solution

We have to calculate the mole fraction of ethanol in the vapor above solution.


The mole fraction of a component in the vapors above the solution is calculated using this formula:

Xa = PaPt

Where,

Xa = mole fraction of a component in vapors above solution

Pa = vapor pressure of a component of solution

Pt = total vapor pressure

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Problem Details

At 63.5oC the vapor pressure of H2O is 175 torr, and that of ethanol (C2H5OH) is 400 torr. A solution is made by mixing equal masses of H2O and C2H5OH.

What is the mole fraction of ethanol in the vapor above the solution?

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