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Simple Freezing Point Problem (I think). Please take a look.?
The problem is: Calculate the freezing point of 0.2molar aqueous solution of CaCl2.
Can you calculate molality from molarity if you don't know the density of the solution, if so, how or else how do you get the freezing point from the given info?
1 Answer
- Trevor HLv 71 decade agoFavorite Answer
You are quite correct. The freezing point depression is calculated from molal solutions not molar. I can think of two reasons why the question is wordrd this way:
1) The person who set the question made a mistake
2) at this dilute solution there is not a lot of difference between molal amd molar.
I propose that you calculate as if it was a 0.2molal solution, with a note pointing out your concerns in this matter.
Alternatively, I checked and found that a 0.2M solution of Ca(Cl)2 that is a concentration of 22.2g/ litre has a density of 1.015g/cm³ .
