# CHEMISTRY

posted by .

At 63.5 degreesC, the vapour pressure of H2O is 23.3kPa and that of ethanol is 53.3kPa. A solution is made by mixing egual masses of H2O and C2H5OH.
a. what is the mole fraction of ethanol in the solution?
b. assuming ideal-solution behaviour, what is the vapour pressure of the solution at 63.5 degreeC.
c. what is the mole fraction of ethanol in the vapour above the solution.

• CHEMISTRY -
• CHEMISTRY -

thenkyou. i missed reading that pert on that page before. i knew it was something simple.
i now have parts A and B but how do you work out C? i have the mole fraction of ethanol from part A. why is it not the same?

• CHEMISTRY -

The mole fraction of the LIQUID is moles liquid component/total moles liquid.
The mole fraction of the VAPOR is moles vapor component/total vapor moles. Since the vapor pressures are not the same the vapor is more concd in the more volatile component. That's one reason fractional distillation works.

• CHEMISTRY -

so do i use the moles i would have from part A? surely not, becayse they just give me the mole fraction of the solution.
what do i use? i have the answer of 0.472- don't know how to get it.
i feel so dumb and have my exam on 23rd.

## Similar Questions

1. ### college chem

. Jack Daniels Tennessee whiskey is 40.00% ethanol by volume. However, % alcohol by mass is quite different from % by volume. The molality of ethanol in an aqueous solution that is 40.00 % ethanol by volume is 10.88 molal. A) Find …
2. ### Chemistry

The vapor pressures of ethanol (C2H5OH) and 1-propanol (C3H7OH) are 100 mmHg and 37.6 mmHg, respectively. Assume ideal behavior and calculate the partial pressures of ethanol and 1-propanol at 35 degrees Celsius over a solution of …
3. ### chemistry

dimethylglyoxime is used as a reagent in qualitative analysis to precipitate the nickel(II) ion. a solution is made by dissolving 57.0 grams of DMG in 430.0 g of ethanol. (a) what is the mole fraction of DMG in this solution?
4. ### CHEM - mole fractions

the vapour pressure of pure water at 110 degrees is 142.7kpa. a solution of ethylene glycol and water has a vapour pressure of 101.3kpa at 110 degrees. assuming that raoults law is obeyed, what is the mole fraction of ethylene glycol …
5. ### Chemistry

A solution is made by mixing equal masses of methanol, CH4O, and ethanol, C2H6O. Determine the mole fraction of each component to at least three significant figures
6. ### chemistry

What is the percent by volume (% v/v) of a solution made by mixing 12 ml of ethanol (C2H5OH) with 48 ml of water?
7. ### Chemistry #11

A solution of ethanol (C2H5OH) is prepared by dissolving 35.0 ml of ethanol in enough water to make 120.0 ml of solution. What is the molarity of the ethanol in this solution?
8. ### chemistry

An aqueous solution contains 64g of ethanol( C2H5OH) in 122 grams of solution. The mole fraction of ethanol is:
9. ### chemistry

When 25 mL of C2H5OH (density 0.80 g.cm-3) is dissolved in water to prepare a 250 mL solution, the density of the solution was found to be 0.950 g.cm-3. Calculate a. Molarity of pure ethanol; b. Molarity of ethanol in the final solution; …
10. ### Chemistry

What is the mole fraction of ethanol, C2H5OH, in an aqueous solution that is 50.0% ethanol by mass?

More Similar Questions