Physical
Vapor pressure & rotovap
Antoine vapor pressure of a solvent, and the boiling point at each vacuum setpoint.
log10(P[bar]) = A − B/(T[K] + C)
Temperature for the vapor-pressure readout (deg C).
Protocol result
⚗ Aliquot
Vapor pressure & rotovap · log10(P[bar]) = A − B/(T[K] + C) · the lab bench, calculated
Antoine✓ log10(P[bar]) = A − B/(T[K] + C)
Water at 25 °C: 31.8 mbar (23.8 mmHg)
1
Boiling point drops as you pull vacuum. Set the bath about 20 °C above the boiling point at your vacuum, and the condenser well below it.
| Vacuum (mbar) | Boils at |
|---|---|
| 1013.25 | 100.5 °C * |
| 500 | 81.3 °C |
| 200 | 59.8 °C |
| 100 | 45.5 °C |
| 50 | 32.7 °C |
| 25 | 21.1 °C |
| 10 | 7.4 °C |
⚠
Rows marked * are outside the fitted temperature range and are extrapolated.
P at temp
0.03 bar
Source
Stull, 1947