Question

When mercuric iodide is added to an aquous solution of KI, the

1. freezing pointis raised
2. freezing point is lowered
3. boiling point does not change
4. freezing point does not change

Answer 1

HgI ₂ + 2KI → K ₂ HgI ₄

Since the number of moles decreases when mercuric iodide react with potassium iodide, therefore freezing point of solution increases.