delta T = i*Kf*molality.
You know i = 3 from CaCl2. You know Kf (or you can look it up). I THINK it's about 1.9 or so. All you need is the molality. You have the M. Convert this way.
Assume you have a liter of solution so the mass of solution is 1000 mL x 1.5 g/mL = 1500 grams. How much of that is CaCl2. grams CaCl2 = mols CaCl2 x molar mass CaCl2 = approx 6 grams but you need to verify that and all of the other estimates I've done.
So grams H2O = 1500-g CaCl2 = grams H2O. Divide by 1000 to convert to kg. Then m = 0.05/kg solvent. Finally, substitute this into the dT = i*Kf*m to find delta T and subtract from the normal freezing point of H2O which is zero. By the way I doubt that the density of that CaCl2 solution is anywhere near 1.5 g/mL.
If a sample of red blood cells at an osmotic pressure of 7.70 atm is placed in a solution that contains 0.050M calcium chloride (CaCl2) at 25°C,
what is the freezing point of this solution if the density of the solution is 1.50 g/mL
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