Q45 / 180 · KCET 2013 · Chemistry
Which of the following aqueous solutions will exhibit highest boiling point?
- A$0.01 \mathrm{M}$ urea
- B$0.01 \mathrm{M} \mathrm{KNO}_{3}$
- Correct answerC$0.01 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}$
- D$0.015 \mathrm{M} \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$
Solution
$\begin{aligned}
\mathrm{NH}_{2} \mathrm{CONH}_{2} & \longrightarrow \text { no dissociation } \\
\mathrm{KNO}_{3} & \longrightarrow \mathrm{K}^{+}+\mathrm{NO}_{3}^{-} ; \quad i=2 \\
\mathrm{Na}_{2} \mathrm{SO}_{4} & \longrightarrow 2 \mathrm{Na}^{+}+\mathrm{SO}_{4}^{2-} ; \quad i=3 \\
\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6} & \longrightarrow \text { no dissociation }
\end{aligned}$
As $\mathrm{Na}_{2} \mathrm{SO}_{4}$ gives maximum particles, i.e., 3 on dissociation boiling point is maximum for $\mathrm{Na}_{2} \mathrm{SO}_{4}$.
Hence, the correct answer is option: 'C'.