Question

a solution is prepared by dissolving 4.9 g C12H22 O11 (nonelectrolyte) in 175 grams of water. calculate the freezing poitn and osmotic pressure (25C) of this solution.

Answer 1

moles in 4.9g = grams/molar mass = ?
m = molality = mols/kg solvent
delta T = Kf*m. Solve for delta T and subtract from the normal freezing point of H2O (0C) to find the new freezing point.

pi = MRT
M is molarity but in dilute solutions M and m are almost the same. R is 0.08206 and T must be in kelvin; pi comes out in atmospheres.

Answer 2

i got 2.002 atm is that right

Answer 3

I get 2.00 atm also. If you have a density in the problem we can correct for and use M and not m but with no density in what you posted we have no choice but to use m for M.