Question

Which one of the following liquids will have the highest
freezing point?
A. pure H2O
B. aqueous glucose (0.050 m)
C. aqueous CoI2 (0.030 m)
D. aqueous FeCl3 (0.030 m)
E. aqueous NaI (0.030 m)

Could you please give a step by step process?

Answer 1

delta T = i*Kf*m
i = 1 for glucose
i = 3 for CoCl2
i = 4 for FeCl3
i = 2 for NaI
(i = van't Hoff factor which is the number of particles in soln). But you really don't need any of that stuff above to answer the question.
Note that pure water freezes at 0 C. ALL solutes will lower the freezing point so B, C, D, and E will lower the freezing point from zero C. The highest freezing point will be .....?
Or you can forget reasoning and solve each of the above equations to determine how much each will be changed.