The ratio of the freezing point depressions of the solution is — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

Both solutions have the same mass percentage (5%), meaning the mass of solute and mass of solvent are the same in both cases. Molality $m \propto 1/M$. Thus, $m_A / m_B = M_B / M_A = 3/1$. Since $\Delta T_f \propto m$, the ratio $\Delta T_f(A) : \Delta T_f(B)$ is $3:1$. Therefore, correct answer is B.