Answer:
B) the freezing point decreases and the vapor pressure at 25°C decreases.
Explanation:
Colligative properties are those properties that depend on the amount of solute in solution. Both freezing point and vapour pressure are colligative properties.
As the number of nonvolatile solute particles increases, the freezing point of the solution decreases. This is known as freezing point depression.
Similarly, "Vapor pressure is a colligative property, so the vapor pressure of solutions is directly proportional to the amount of solute present in a solution. When a solute is present in a solvent, the vapor pressure is lowered because fewer solvent molecules are present at the top of the solution" (Lumen Learning).
