chemistry

What is the mole ratio of benzene (C6H6) to n-octane in the vapor above a solution of 15.0% benzene and 85.0% n-octane by mass at 25 degrees Celcius? the vapor pressures of n-octane and benzene are 11 torr and 95 torr.

  1. 👍 0
  2. 👎 0
  3. 👁 2,085
  1. 15% benzene means 15g benzene/(15g benzene + 85 g octane).
    15/molar mass benzene = mols benzene.
    85/molar mass octane = mols octane.

    Calculate Xbenzene
    Calculate Xoctane.
    Then pBen = XBen*Pobenzene
    and pOct = XOct*Pooctane

    Then Ptotal = Pbenzene + Poctane

    1. 👍 0
    2. 👎 0
  2. here is what I did (check my work, because something isnt right):

    15g C6H6/78.12gC6H6 = .19 mol C6H6
    85g C8H18/114.26g C8H18= .74 mol C8H18

    X-benzene: .19/.93= .204
    X-octane: .74/.93= .796

    pBen: .204*95=19.38
    pOctane: .796*11=8.756

    19.38+ 8.756= 28.136

    1. 👍 0
    2. 👎 0
  3. That looks ok to me. You haven't been consistent with significant figures. If your database and prof are picky about that you need to go through and make some changes.

    1. 👍 0
    2. 👎 0
  4. The database said the answer was 2.23 ??

    1. 👍 0
    2. 👎 0
  5. That' because you and I didn't finish the question. Go back and look at the problem. It asks for the benzene/octane RATIO. So take pbenzene/poctane. Using your numbers that is 19.38/8.756 = 2.21 and I suspect the difference (2.21 vs 2.23) is one of significant figures through the computation.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. general chemisty

    Calculate the freezing point of a solution of 20.0 g methyl salicylate, C7H6O2, dissolved in 800 g of benzene, C6H6. Kf for benzene is 5.10°C /m and the freezing point is 5.50°C for benzene. A) -1.05°C B) 1.05°C C) 4.45°C D)

  2. Chemistry

    A solution contains 10.0 g pentane, C5H12, 10.0 g hexane, C6H14 and 10.0 g benzene, C6H6. What is the mole fraction of hexane? I figured the equation would be: ___ M Hexane x 10 Divided by 30 =Mole fraction of Hexane?

  3. chemistry

    6.70 A sample of benzene, C6H6, weighing 3.51g was burned in an excess of oxygen in bomb calorimeter. The temperature of the calorimeter rose from 25.00C to 37.18C. If the heat capacity of the calorimeter and contents was

  4. ap chemistry

    a solution is prepared by mixing 50.0 mL toluene (C6H5CH3 d=0.867 g/mL) with 125 mL Benzene (C6H6 d=0.874 g/mL). assuming that the volumes add upon mixing, calculate the mass percent, mole fraction, molality, and molarity of the

  1. chemist

    If 50.0 g of benzene, C6H6, at 25.0 °C absorbs 2.71 kJ of energy in the form of heat, what is the final temperature of the benzene? The specific heat capacity of benzene is 1.72 J/g ⋅K.

  2. chemistry

    Benzene, C6H6, is a known carcinogen that burns in air according to the following unbalanced equation: C6H6(l) + O2(g)  CO2(g) + H2O(g) a. What is the mole ratio of O2 to C6H6? b. How many moles of O2 are required to react with

  3. chemistry

    At a given temperature, you have a mixture of benzene (vapor pressure of pure benzene = 745 torr) and toluene (vapor pressure of pure toluene = 290 torr). The mole fraction of benzene in the vapor above the solution is 0.590.

  4. 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

  1. Chemistry

    Which pair of compounds will form a solution? A) Benzene (C6H6) and Hexane (C6H14) B) Na2SO4 and Benzene C) NaCl and Hexane

  2. Chemistry

    Which pair of compounds will form a solution?Benzene (C6H6) and hexane (C6H14)Na2SO4 and benzene (C6H6)NaCl and hexane (C6H14)H2O and CCl4More than one of the combinations above will form solutions.

  3. Chemistry

    Carbon tetrachloride (CCl4) and benzene (C6H6) form ideal solutions. Consider an equimolar solution of CCl4 and C6H6 at 25°C. The vapor above this solutionis collected and condensed. Using the following data, determine the

  4. AP Chemistry

    1,2-Benzanthracene is a yellow-brown nonvolatile solid with molecular weight 228.29g*mol-1. an 18.2632-g sample of 1,2-benzanthracene is dissolved in 250.0 g of benzene, C6H6. Whta is the vapor pressure of this solution at 25C, in

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