Boiling point elevation \(\propto i \times m\) (van't Hoff factor \(\times\) molality). Na\(_2\)SO\(_4\): \(i=3\), effective molality \(=0.03\). Glucose: \(i=1\), \(=0.015\). Urea: \(i=1\), \(=0.01\). KNO\(_3\): \(i=2\), \(=0.02\). Highest: \(0.01\text{M}\ \text{Na}_2\text{SO}_4\) with effective particles \(=0.03\).