AP CHEM

posted by .

I'm currently working on a lab in which I have to make the solution boil at 245 degrees F. The solution will be a mix of ethylene glycol and I have to caluculate the volumes of water and solute needed to make the solution.

here's my work so far.
X= mL C2H4(OH)2
175mL-X=mL H20

water boils @ 100 degrees C
my bp is 118.33 degrees C

given:
kb= .515 degrees C kg/mol
d of C2H4(OH)2 = 1.1088 g/mL

delta Tb = (kb*g*i)/GMW*kg

18.33 degrees c = (.515)*(1.1088)*(1)/(62.08g/mol)*(175-X(.9970)/1000)
18.33 = .571032X/(62.08)(175-X)(.9970)/1000
18.33 = 571.032 X/(62.08)(174.475-.9970X)
18.33 = 571.032X/ (1031.408-61.89376X)

now i'm stuck. i don't understand how to get x by itself from here. is what i've done so far correct?
thank you.

  • AP CHEM -

    I got cross eyed looking at all the numbers. Let me break it down. Also, you don't say how much you want to make. I have assumed 100 g water as the solvent.
    Delta T = Kb*m (i is 1).
    118.33-100 = 0.515*m
    solve for molality.

    molality = mols solute/kg solvent = mols solute /0.1
    solve for moles solute.

    mols solute = grams solute/molar mass solute

    If you want to use volume for the ethylene glycol instead of weighing it, then volume = mass desired/density

    I hope this helps.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chem=continued

    I'm currently working on a lab in which I have to make the solution boil at 245 degrees F. The solution will be a mix of ethylene glycol and I have to caluculate the volumes of water and solute needed to make the solution. here's my …
  2. CHM 152

    An automobile antifreeze contains equal volumes of ethylene glycol (d=1.114 g/mL and FW = 62.07) and water (d=1.00 g/mL) at 25oC. The solution has a density of 1.06 g/mL. What is the molarity of ethylene glycol in the solution?
  3. 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 …
  4. physics

    an antifreeze solution is made by mixing ethylene glycol (density= 1116 kg/m^3) with water. suppose that the specific gravity of such a solution is 1.0730. assuming that the total volume of the solution is the sum of its parts, determine …
  5. Chem

    a) An ethylene glycol solution contains 21.1 g of ethylene glycol in 86.0 ml of water. compute the freezing point of the solution. b) Compute the boiling point of the solution.
  6. chem

    An ethylene glycol solution contains 23.9 g of ethylene glycol (C2H6O2) in 86.9 mL of water. Compute the freezing point and boiling point of the solution. (Assume a density of 1.00 g/mL for water.)
  7. chemistry

    Okay so I know how I would normally determine molar mass of a compound *get out periodic table, sum up elements present, eg. H20 = [2(1.008)+16.00]g/mol* But this is for a lab class and they want us to derive it. Info found: Ethylene …
  8. Math

    A chemist has two ethylene glycol and water solutions: one that contains 11.98% ethylene glycol and another with 7.30% ethylene glycol. How many litres of each must be mixed to make 7.50 x 102 L containing 10.50% ethylene glycol?
  9. chem

    An ethylene glycol solution contains 21.5 of ethylene glycol in 82.9 of water.
  10. Chemistry 2

    we make a solution of water and ethylene glycol c2h4(oh)2 which contains 24 g of the glycol for each 74 g of water. What is the boiling point of ethylene?

More Similar Questions