Boiling and Freezing Points of Solutions

[Qube]

Homework Statement

The aqueous solution with the lowest freezing point of the following group is:

1) 0.01m MgSO4
2) 0.01m NaCl
3) 0.01m CH3CH2OH
4) 0.008m MgCl2
5) all equal

Homework Equations

Solutions have lower freezing points and higher boiling points than their solvents.

CH3CH2OH is a non-electrolyte. It will not dissolve.

The Attempt at a Solution

I don't know exactly how to estimate the freezing point. I'm assuming it has something to do with the concentration of the ions. In that case it seems as if 0.008m of MgCl2 would dissolve into the most ions (Mg2+ and 2Cl-). Although it has a lower molarity, it dissolves to form one Mg2+ and 2Cl-, unlike all the other 0.01m solutions, which only dissolve to form one cation and one anion.

 

[SteamKing]

http://chemwiki.ucdavis.edu/Physica...ligative_Properties/Freezing_Point_Depression

 

[Borek]

You are on the right track. Google for Van 't Hoff factor.