Question

Which of the following solution will have the highest boiling point?

• A. 1% solution of glucose in water
• B. 1% solution of sucrose in water
• C. 1% solution of sodium chloride in water
• D. 1% solution of calcium chloride in water

Answer 1

Answer: (C)

For glucose, sucrose, $i=1$. For $NaCl$ and $CaC{l}_2$, the values of van't Hoff

factor are 2 and 3 respectively. $\Delta T_b=k_b(im)$

So effective $\Delta T_f$ for glucose, sucrose, $NaCl$ and $CaC{l}_2$ $\propto \frac{1\times 10}{180},\frac{1\times 10}{342},\frac{2\times 10}{58.5}$ and $\frac{3\times 10}{111}$

Thus, elevation in boiling point is maximum in case of $NaCl$ solution and hence, $NaCl$ would have maximum boiling point. (Boiling point of solution = Boiling point of solvent $+\Delta T_b$