Out of three 1.5 m solutions of glucose, sodium sulfate, and ammonium phosphate which will have the highest boiling point, lowest freezing point and lowest vapor pressure

Explanation:

Increase of boiling point, decrease of freezing point, and decrease of vapor pressure are all colligative properties.

The colligative properties are the physical properties of the solutions that depends on the number of particles of solute dissolved and not on the nature of the particles.

Regarding the vapor pressure of a solution, since the solute particles occupy part of the surface of the solution, less solvent particles are in the surface and so the vapor pressure decreases. The higher the number of solute particles, the greater the decrease on the vapor pressure.

As for the boiling boiling point, take into account that the boiling points is the temperature at which the vapor pressure of the substance reachs the atmospheric pressrue. Since, the presence of solute particles diminishes the vapor pressure of the solution, the solutions will need to absorb more energy to reach the atmospheric pressure, meaning that the boiling point will be higher. The higher the number of solute particles, the greater the increase on the boiling point.

As for the freezing point, the solutions freeze at lower temperatures when a solute is added. The higher the number of particles of solute, the lower the freezing point of the solution.

Then, you need to find which out of three 1.5 m (molal) solutions of glucose, sodium sulphate, and ammonium phosphate will produce the greater number of particles.

Glucose is a molecular compound (not ionic), so each molecule of glucose will yield one particle.

Sodium sulphate is Na₂SO₄; a ionic compound that ionizes into 3 ions: 2 Na⁺ and 1 SO₄²⁻.

Ammonium phospahte is (NH₄)₃ PO₄; a ionic compound that ionizes into 4 particles: 3 NH₄⁺ and 1 PO₄³⁻.

Therefore, since every unit of ammonium phosphate yields to more particles than every unit of glucose or sodium sulphate, the 1.5 m solution of ammonium phosphate will have the most impact on the colligative properties.