Calculate boiling temperature from pressure and constants. Export results, compare scenarios, and review example table. Keep separations efficient with lower heat exposure and degradation.
This example uses sample Antoine constants for toluene.
| Compound | Pressure (mmHg) | Pressure (kPa) | Estimated Boiling Point (°C) |
|---|---|---|---|
| Toluene | 760.00 | 101.33 | 110.63 |
| Toluene | 400.00 | 53.33 | 89.49 |
| Toluene | 200.00 | 26.66 | 69.50 |
| Toluene | 100.00 | 13.33 | 51.94 |
| Toluene | 50.00 | 6.67 | 36.40 |
| Toluene | 25.00 | 3.33 | 22.53 |
Vacuum distillation lowers boiling temperature by lowering absolute pressure. This calculator uses the Antoine equation for vapor pressure and boiling point estimation.
Antoine equation:
log10(P) = A - B / (C + T)
Boiling point form:
T = B / (A - log10(P)) - C
Where:
Supporting calculations:
Use Antoine constants that match the correct chemical and temperature range. For engineering design, validate final values with trusted phase-equilibrium data.
The result appears below the header and above the form after submission.
Vacuum distillation is used when a compound boils too hot at normal pressure. Lower pressure lowers the boiling temperature. That helps protect heat-sensitive materials. This vacuum distillation calculator estimates the boiling point at reduced pressure with Antoine constants. It also converts pressure and compares vacuum boiling point with normal boiling point.
Many organic compounds degrade, darken, or react when heated too strongly. Reduced pressure allows separation at milder temperatures. This is useful in laboratory purification, solvent recovery, resin handling, and process development. A faster pressure check can improve setup choices before running the flask, column, and condenser.
The calculator uses operating pressure, pressure unit, Antoine constants, and current liquid temperature. It converts the entered pressure to mmHg. Then it estimates the boiling point at that pressure. It also estimates the normal boiling point at 760 mmHg. From those values, it reports boiling point reduction, vacuum level, pressure ratio, and vapor pressure at the entered liquid temperature.
If the current liquid temperature is below the predicted boiling point, the system may need more heat or lower pressure. If the liquid temperature is near the calculated point, steady boiling may begin soon. If the temperature is already above that point, rapid vapor formation is more likely. Always check bumping risk, condenser capacity, and receiver cooling.
Antoine constants only work well within their valid temperature range. Use reliable data for the exact compound. Mixed systems can behave differently from pure-component estimates. For production work, also check relative volatility, pressure control stability, and hold-up in the apparatus. Even with those limits, this tool gives a strong first estimate for vacuum distillation planning.
Vacuum distillation is a separation method performed below atmospheric pressure. Lower pressure lowers boiling temperature. That helps purify materials that may decompose, oxidize, or discolor at higher temperatures.
A liquid boils when its vapor pressure matches surrounding pressure. Under vacuum, the surrounding pressure is lower. The liquid reaches that condition at a lower temperature.
Antoine constants are empirical values used to estimate vapor pressure and boiling temperature. Each compound has its own constants, and they usually apply only over a limited temperature range.
This page is best for pure-component estimates. Real mixtures can show non-ideal behavior. For precise design, use vapor-liquid equilibrium data, activity models, or measured distillation information.
Enter the pressure in the unit you actually measure. The calculator converts it internally. Common lab units include mmHg, torr, kPa, mbar, and bar.
Check the pressure unit first. Then verify Antoine constants and temperature range. A wrong constant set or a unit mismatch can shift the estimated boiling point dramatically.
Yes. It shows whether the liquid is below, near, or above the estimated boiling point at the chosen pressure. That helps assess heating demand and boiling behavior.
Yes. Use the CSV button to download table data. Use the PDF option to print the page or save it as a PDF from your browser.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.