Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Ideal binary liquid at one temperature. Both pure-component vapor pressures must be at that same temperature.
Example Calculation
- Liquid mole fraction of A: 0.4
- Pure A vapor pressure: 100 kPa
- Pure B vapor pressure: 50 kPa
xA=0.4, PA*=100 kPa and PB*=50 kPa give total pressure 70 kPa.
Method references
Frequently asked questions
How do I use this calculator?
Enter liquid mole fraction of a, pure a vapor pressure, pure b vapor pressure. The result updates automatically. Use Reset to restore the example values.
What method does it use?
P=xA PA*+(1−xA)PB*.. Ideal binary liquid at one temperature. Both pure-component vapor pressures must be at that same temperature.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.