An aqueous solution containing 0.25 moles of a non-volatile but strong electrolyte solute ‘X’ in 500 — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

Molality $m = \text{moles} / \text{kg solvent} = 0.25 / 0.500 = 0.5 \text{ m}$. $\Delta T_f = i \times K_f \times m \Rightarrow 2.79 = i \times 1.86 \times 0.5 \Rightarrow 2.79 = i \times 0.93 \Rightarrow i = 2.79 / 0.93 = 3$. For a strong electrolyte, $i$ equals the number of ions. Therefore, correct answer is C.