Mole fraction of a vapor pressure?

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 cyclohexane-acetone solution is composed of both cyclohexane vapor and acetone vapor. What mole fraction of the vapor above the solution (XeyVapor)is cyclohexane?
i got the mole fraction of cyclohexane in the solution(.405) but that isn't what it wants and I don't know exactly what the question is asking for.

  1. 👍 0
  2. 👎 0
  3. 👁 2,046
  1. In the vapor phase,mole fraction will be in the same proportion as the pressure fractions.

    Pey=97.6*1.50/3.7=40 about
    Pac=229.5*2.2/3.7=136 about

    Mole fraction ey= about 40/176=
    Mole fraction vac=about 136/176

    1. 👍 0
    2. 👎 0
    👨‍🏫
    bobpursley
  2. I see where i went wrong. I was trying to take the mole fraction (.405) and divide it into the 176.
    Thank you.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    Predict whether the following reactions will be exothermic or endothermic A) N2(g)+ 3H2(g) --> 2NH3(g) B) S(g) +O2(g) ---> SO2(g) C) 2H2O(g) ---->2H2(g) + O2(g) D) 2F(g) +F2(g) Bond H-H 432 kj/mol N-N(triple bond) 942 kj/mol O=O

  2. Chemistry

    1)The chemical formula for aspirin is C9H8O4. What is the mass of 0.40 mol of aspirin? How would I find this? 2)The gram molecular mass of oxygen is 16.0 g right? 3)How would I find the mass, in grams, of 3.01 x 10^23 molecules of

  3. ap chem

    calculate the lattice enthalpy of potassium fluoride from the following data: enthalpy of formation of K(g): +89 kJ · mol−1 first ionization energy of K(g): +418 kJ · mol−1 enthalpy of formation of F(g): +79 kJ · mol−1

  4. Chemistry

    Which of the reactions are spontaneous (favorable)? a. 2H2O(g)⟶2H2(g)+O2(g) Δ𝐺=457 kJ/mol b. CH4(g)+2O2(g)⟶CO2(g)+2H2O(l) Δ𝐺=−820 kJ/mol c. 2Mg(s)+O2(g)⟶2MgO(s) Δ𝐺=−1137 kJ/mol d. C(s)+H2O(l)⟶CO(g)+H2(g)

  1. chemistry 101

    How many moles of oxygen are in 3.45 mol of diphosphorus pentoxide? options: 5.75 mol O 13.5 mol O 6.90 mol O 3.45 mol O 17.3 mol O

  2. Chem for final, please help!

    How many moles of H+(aq) ions are present in 1.25 L of 0.75M Nitric Acid? A. 0.60 mol B. 0.75 mol C. 0.94 mol D. 1.7 mol E. 1.9 mol Please show me how to work this!

  3. chemistry

    If 15.0 grams of C3H6, 10.0 grams of oxygen, and 5.00 grams of NH3 are reacted, what mass of acrylonitrile can be produced assuming 100% yield, what mass of the excess reactants remain? 15g C3H6 (1 mol / 42.08 g) = .35 mol C3H6

  4. Chemistry

    According to the reaction 2Al+3H2SO4→3H2+Al2(SO4)3, the total number of moles of H2SO4 needed to react completely with 5.0 mol of AL is 1. 2.5 mol 2. 5.0 mol 3. 7.5 mol 4. 9.0 mol

  1. chemistry

    2Na3PO4 + 3CaCl2 ----> Ca3 (PO4)2 + 6NaCl how many moles of CaCl2 remain if .10 mol Na3PO4 and .40 mol CaCl2 are used? When amounts of both materials are listed one must worry about which is the limiting reagentalthough the

  2. chemistry

    3CuCl2 *2H2O + 2Al = 3Cu + 2AlCl3 + 6H2O Determine the number of grams that should have been produced when 1.25g of copper (2) chloride dehydrate reacts with excess aluminum so i'm not really sure how you're supposed to calculate

  3. Chemistry

    2KClO3 --> 2KCl + 3O2 What mass of O2 can be made from heating 125 g of KClO3? I know that the answer is 49 g O2 but I keep getting a completely different answer, can anyone show me what I'm doing wrong? 125g KClO3 x (2 mol KClO3/

  4. chemistry

    Calculate the theoretical percentage of water in gypsum, rounded to the nearest whole number %. (calcium sulfate dihydrate; CaSO4 ° 2H2O; Ca = 40 g/mol, S= 32 g/mol; O= 16 g/mol; H= 1 g/mol).

You can view more similar questions or ask a new question.