Question:
What is the relation between elevation in boiling point and molality?
What is the relation between elevation in boiling point and molality?
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Colligative properties like boiling point elevation depend only on the number of solute particles, not on their nature. Always convert mass of solvent into kilograms while using molality.
Updated On: Sep 3, 2025
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Solution and Explanation
The elevation in boiling point (\(\Delta T_b\)) is directly proportional to the molality (\(m\)) of the solution.
\[ \Delta T_b = K_b \cdot m \]
Where:
- \(\Delta T_b = T_b - T_b^\circ\), elevation in boiling point,
- \(K_b\) = molal elevation constant (ebullioscopic constant) of the solvent,
- \(m\) = molality of the solution (mol solute per kg solvent).
Thus, higher the molality of the solution, greater is the elevation in boiling point.
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