The molecular mass of NaCl as determined by osmotic pressure measurement is — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

NaCl dissociates into $\text{Na}^+$ and $\text{Cl}^-$ ions, yielding more particles than expected ($i > 1$). Since colligative properties (like osmotic pressure) are inversely proportional to observed molecular mass, the calculated molecular mass will be less than the theoretical value of 58.5. Therefore, correct answer is B.