Question

When mercuric chloride is added to the aqueous solution of potassium iodide, then ______.

Options

• the boiling point does not change

• the freezing point is raised

• the freezing point is lowered

• the freezing point does not change

Answer 1

When mercuric chloride is added to the aqueous solution of potassium iodide, then the freezing point is raised.

Explanation:

When mercuric chloride is added to KI solution, a complex ion [HgI₄]⁻² is formed, which reduces the number of free ions in the solution. Since colligative properties depend on the number of solute particles, the freezing point depression decreases, thus raising the freezing point.