As the solute dissolved into a liquid increases, the freezing point ____________.

As the solute dissolved into a liquid increases, the freezing point ____________.

• A. Decreases
• B. Increases
• C. Stays the same
• D. Oscillates

Answer: (A)

Freezing point depression is the idea tested here: dissolving more solute lowers the temperature at which a liquid freezes. When soluble particles are present, they disrupt the orderly arrangement of solvent molecules needed to form a solid lattice. To reach the equilibrium where solid and liquid can coexist, the system must be cooled to a lower temperature. The more solute particles there are, the greater this disruption, so the freezing point drops further. This relationship is captured by ΔTf = i Kf m, meaning the decrease in freezing point grows as the molality of dissolved particles increases. Since adding solute increases m, the actual freezing point becomes lower, not higher.

Freezing point depression is the idea tested here: dissolving more solute lowers the temperature at which a liquid freezes. When soluble particles are present, they disrupt the orderly arrangement of solvent molecules needed to form a solid lattice. To reach the equilibrium where solid and liquid can coexist, the system must be cooled to a lower temperature. The more solute particles there are, the greater this disruption, so the freezing point drops further. This relationship is captured by ΔTf = i Kf m, meaning the decrease in freezing point grows as the molality of dissolved particles increases. Since adding solute increases m, the actual freezing point becomes lower, not higher.