The boiling point elevation $\Delta T_b$ of a dilute solution is:
- Directly proportional to molality
- Independent of molality
- Proportional to mole fraction of solvent
- Inversely proportional to molality
Show answer and solution
Correct answer: A. Directly proportional to molality
$\Delta T_b = K_b m$, directly proportional to molality $m$.
$K_b$ is the ebullioscopic (molal elevation) constant — the BP elevation produced by a 1 molal solution.