An aqueous solution of non-volatile, non-electrolyte solute boils at . It should freeze at (for wate — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

Elevation in boiling point $\Delta T_b = 100.78 - 100 = 0.78^\circ\text{C}$. Molality $m = \Delta T_b / K_b = 0.78 / 0.52 = 1.5 \text{ m}$. Depression in freezing point $\Delta T_f = K_f \times m = 1.86 \times 1.5 = 2.79^\circ\text{C}$. The freezing point is $0 - 2.79 = -2.79^\circ\text{C}$. Therefore, correct answer is C.