Higher the value of van't Hoff factor (i), higher will be depression in freezing point and lower will be the freezing point of solution. So, ′i′ value, 0.2MK2SO4=3 0.2MKCl=2 0.2MNaNO3=2 0.2MMgSO4=2 Hence, 0.2MK2SO4 will have lowest freezing point.