Posted by Sar on .
If 0.380 mol of a nonvolatile nonelectrolyte are dissolved in 3.00 mol of water, what is the vapor pressure P(H2O) of the resulting solution? The vapor pressure of pure water is 23.8 torr at 25 C.
I got this answer correct: 21.1 torr
A solution is composed of 1.50mol cyclohexane (Pey=97.6torr) and 2.20 mol acetone (P=229.5torr). What is the total vapor pressure (Ptotal) above this solution?
I got the correct answer: 176 torr
However, I am confused about part B. Can anyone help explain how to do this problem?
As you saw in Part B, the vapor above the cyclohexaneacetone solution is composed of both cyclohexane vapor and acetone vapor. What mole fraction of the vapor above the solution, , is cyclohexane?

Chemistry: Raoult's Law 
SraJMcGin,
Some of th e following might help you:
http://search.yahoo.com/search?fr=mcafee&p=Raoult%27s+Law
Sra 
Chemistry: Raoult's Law 
Sar,
i got the mole fraction of cyclohexane in the solution but that isn't what it wants and I don't know exactly what the question is asking for.
Can someone please explain to me how to do this problem?