Boiling Point Elevation

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Calculate how much the boiling point of a solvent increases when a solute is added.

Reaction Parameters

Ebullioscopic Constant (Kb)

°C/m

Molality (m)

mol/kg

Van 't Hoff Factor (i)

Calculation Results

Enter parameters to calculate the boiling point elevation

About this calculator

Overview

Boiling point elevation is a colligative property that depends on the number of solute particles in solution, not their chemical identity. When non-volatile solutes are added to a solvent, they disrupt the solvent's ability to evaporate, requiring higher temperatures to reach the boiling point. This principle is fundamental to understanding phase changes in solutions and has important applications in cooking, automotive cooling systems, and industrial processes.

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Pro Tips

The Van 't Hoff factor (i) represents the number of particles the solute dissociates into (e.g., i=2 for NaCl, i=3 for CaCl₂, i=1 for sugar).
Molality (m) is defined as moles of solute per kilogram of solvent - use this instead of molarity for colligative properties as it doesn't change with temperature.
The ebullioscopic constant (Kb) is specific to each solvent: water (0.512°C/m), benzene (2.53°C/m), ethanol (1.22°C/m), carbon tetrachloride (5.03°C/m).
For accurate results, ensure your solute is completely soluble and non-volatile at the boiling point of the pure solvent.
This calculation gives the elevation above the pure solvent's boiling point - add this to the solvent's normal boiling point for the solution's boiling point.

Fun Facts

"Adding 58 grams of salt per kilogram of water increases the boiling point by only about 0.5°C - a seemingly small change with big implications."
"Salt doesn't actually make water 'boil faster' - it raises the boiling temperature but decreases the specific heat capacity, so the net cooking effect is minimal."
"Antifreeze in car radiators uses boiling point elevation to prevent engine overheating, while simultaneously using freezing point depression to prevent freezing in cold weather."
"Pure water boils at 100°C at sea level, but adding any non-volatile solute immediately raises this temperature due to decreased vapor pressure."
"The boiling point elevation constant (Kb) for water is 0.512°C/m, meaning 1 mole of any non-volatile solute in 1 kg of water raises the boiling point by 0.512°C."
"Ionic compounds like NaCl have higher effects because they dissociate into multiple particles (i=2), while molecular compounds like sugar remain as single particles (i=1)."
"This principle explains why seawater boils at a slightly higher temperature than freshwater, though the difference is too small to notice in cooking."

Formula: ΔTb = i × Kb × m