which solution has highest freezing point if all are at the same molality

calcium chloride
sodium nitrate
potassium sulfate
iron(III) nitrate
all have same freezing point

please explain

1 answer

look at the formulas:
CaCl2 ...three particles
NaNO3....two particles
K2SO4...three
Fe(NO3)3...four
Fe(NO3)3 will have the lowest freezing point (greatest freezing point depression), and sodum nitrate has the least depression, so it will have the highest fp.