Answer:
- Option B. Calcium chloride (CaCl₂)
Step-by-step explanation:
The colligative properties depend on the concentration of particles (molecules or ions) of solute dissolved and not on the identity of the solute.
For your reference the colligative properties are: i) boiling point increase, ii) freezing point depression, iii) vapor pressure lowering, and iv) osmotic pressure.
When the solute is a ionic compound the ionization yields several ions, so for ionic solutes you must predict first the number or ions formed per unit of compound and then predict the effect on the colligative properties: the greater the number of ions per unit of compound the greater the effect on colligative properties.
So, just set the ionization equations for each compound:
- MgSO₄ (aq) → Mg²⁺ (aq) + SO₄²⁻ (aq): 2 ions
- CaCl₂ (aq) → Ca²⁺ (aq) + 2Cl⁻ (aq) : 3 ions
- KI (aq) → K⁺ (aq) + I⁻ (aq): 2 ions
- C₆H₁₂O₆ is a molecular compound, not a ionic one, so it remains s 1 molecule.
Then, since calcium chloride, CaCl₂, produces the greater number of ions it is the solute that productes the greatest effect on colligative properties.