Boiling Point Elevation Calculator
How far a dissolved substance raises the boiling point of a solvent.
Results
Temperature rise
1.02400
K
Boiling point
101.0240
°C
Molality
2.00000
mol/kg
What this tool does
The effect is real but small: the salt a cook puts in pasta water raises its boiling point by a fraction of a degree, nowhere near enough to speed anything up. Water's ebullioscopic constant is 0.512 K·kg/mol, about a quarter of its freezing constant, which is why freezing shows the effect far more dramatically.
Formula
ΔTb = i × Kb × b
Variables
| Symbol | Meaning | Unit |
|---|---|---|
kb | Ebullioscopic constant | K·kg/mol |
bb | Molality | mol/kg |
iv | van 't Hoff factor | — |
tb | Boiling point | °C |
DT | Temperature rise | K |
TN | Boiling point | °C |
BM | Molality | mol/kg |
Worked example
- Ebullioscopic constant0.512 K·kg/mol
- Molality1 mol/kg
- van 't Hoff factor2
- Boiling point100 °C
- Temperature rise1.02400 K
- Boiling point101.0240 °C
- Molality2.00000 mol/kg
Limitations
- For work that must comply with a standard or be signed off, check the result against the applicable code and have it reviewed by a qualified engineer.
- The formula assumes ideal conditions: no friction losses, no air resistance and no efficiency losses unless you enter them.
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.