Soutions are made that contain 0.1 moles of each of the following compunds below in 100 of H2O. Choose the compounds whose solutions will have the lowest freezing point.

Question

A)MgCl2
B)MgSO4
C)KClO3
D)CO2
E)NaBr

Answer 1

100 WHAT of H2O?? grams? That's 0.1 kg.
Use delta T = i*Kf*m
where i is the van't Hoff factor (the number of particles in solution). m is the same, Kf is the same, the only thing changing is i. You CAN do it the long way and calculate each BUT you can look at it and know which is the larger delta T by inspection.