What is the molecular mass of a non-ionizing solid if 10 g of this solid, when dissolved in 100 g of — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

Depression $\Delta T_f = 1.24^\circ\text{C}$. Using $\Delta T_f = K_f \times (w / (M \times W_{\text{kg}}))$, we get $1.24 = 1.86 \times (10 / (M \times 0.1))$. Rearranging yields $M = (1.86 \times 100) / 1.24 = 150 \text{ g/mol}$. Therefore, correct answer is B.