Answer:
The freezing point of a solution is lowered compared to the freezing point of the pure solvent. The amount of depression of the freezing point is proportional to the molality of the solute. The greater the molality of a solution, the lower its freezing point. To compare the freezing points of these solutions, we need to determine which one has the highest molality.
First, we need to determine the number of particles that each solute will produce in solution, as this affects the amount of depression of the freezing point.
KNO3 dissociates into two ions: K+ and NO3-, so it will produce two particles per formula unit.
BaCl2 dissociates into three ions: Ba2+ and two Cl-, so it will produce three particles per formula unit.
Ethylene glycol does not dissociate in solution, so it will produce one particle per molecule.
Na3PO4 dissociates into four ions: three Na+ and one PO43-, so it will produce four particles per formula unit.
Now, we can calculate the molality (moles of solute per kilogram of solvent) for each solution:
For 0.10 m KNO3: molality = 0.10 mol / 1 kg = 0.10 m
For 0.10 m BaCl2: molality = 0.10 mol x 3 particles / 1 kg = 0.30 m
For 0.10 m ethylene glycol: molality = 0.10 mol / 1 kg = 0.10 m
For 0.10 m Na3PO4: molality = 0.10 mol x 4 particles / 1 kg = 0.40 m
So, the solutions in order of decreasing freezing points are:
0.10 m Na3PO4 (highest molality)
0.10 m BaCl2
0.10 m KNO3 and 0.10 m ethylene glycol (same molality, but KNO3 has a smaller van't Hoff factor than ethylene glycol, so it will have a slightly higher freezing point)
Step-by-step explanation: