Posted by **Tommy** on Sunday, March 7, 2010 at 10:53pm.

Can anyone direct me on how to solve this problem? All of the variables are makin my head spin--not sure how to organize them. If you can give equations to use that would help.Thnx!

1 L of an impure water solution has a freezing point of -11 °C. Which of the following is the

best estimate of the vapor pressure of the solution at 25 °C? Assume the vapor pressure of pure

water at 25oC = 23.76 atm, kF = 2 (K kg)/mol, and that water is 55 mol/L. Assume the density of

water is 1 g/mL.

- P. Chemistry -
**DrBob222**, Sunday, March 7, 2010 at 11:08pm
delta T = Kf*molality

11 = Kf*m

Calculate m

molality = moles/kg solvent.

I think we must assume 1 kg solvent although that won't be exactly right.

Calculate (estimate) # moles.

#moles + 55.5 for H2O = total moles.

Calculate mole fraction water,

Then vapor pressure H2O = mole fraction water x 23.76 BUT I don't think that is atm (It must be torr or mm Hg). This would be an estimate at best. Check my thinking.

## Answer this Question

## Related Questions

- Geometry :( - this maths problem is wrecking my head.... 1.find the points of ...
- Alg 2 - Today we learned how to solve systems of equations with 3 variables, ...
- Algebra - I keep confusing myself when I look at this word problem. I am not ...
- College Algebra - Translate the problem into a pair of linear equations in two ...
- physics - "Free-fall" Assigning Variables: Acceleration: If an object is going ...
- Algebra - Translate each problem into a system of equations. DO NOT attempt to ...
- math - Suppose you are in the market for a new home and are interested in a new...
- math - Suppose you are in the market for a new home and are interested in a new...
- quick question regarding equations - I know there are methods out there but what...
- Physics - 1. How much energy is required to be removed to lower the temperature ...

More Related Questions