Vapor Pressure Calculator
What vapor pressure follows from a nonvolatile solute's solvent mole fraction? Enter the stated values to calculate this model.
Reference calculation or estimate for example inputs; assumptions and limitations apply.
Calculations run in your browser.
Assumptions / Standards / Limitations
Raoult ideal-solution approximation assumes one volatile solvent with nonvolatile solute and pure-solvent vapor pressure at the same temperature. Nonideal mixtures or multiple volatile components require another model. This is not a container/storage/pressure-relief design.
Model reference: OpenStax Chemistry 2e; supplementary IUPAC definition where listed. Last verified: 2026-10-08. This is a scientific reference model; no regulatory code or installation standard is used.
Example inputs illustrate the calculation. They are not recommended preparation, installation or operating settings.
What to enter
| Input | Meaning and units |
|---|---|
| Solvent mole fraction (1) | Enter solvent mole fraction in 1; use the same basis as the other measurements. |
| Pure-solvent vapor pressure (Pa) | Enter pure-solvent vapor pressure in Pa; use the same basis as the other measurements. |
Understanding your result
The result is a scientific reference calculation under the model assumptions on this page. It does not assess hazards, chemical compatibility, purity, solubility, equipment limits or clinical meaning.
Common mistakes
- Using solvent volume in place of final solution volume, or mass concentration in place of molar concentration.
- Ignoring units, reaction coefficients, activity assumptions or the stated temperature/model limits.
Check your calculation
- Check the units and balance/coefficients against the worked example. For real laboratory work, verify SDS information and the applicable procedure independently.
Calculation checks, sources and review limits
What vapor pressure follows from a nonvolatile solute's solvent mole fraction?
What vapor pressure follows from a nonvolatile solute's solvent mole fraction? Enter the stated values to calculate this model.
Common uses
- What vapor pressure follows from a nonvolatile solute's solvent mole fraction
How it works
Multiply the solvent mole fraction by the pure-solvent vapor pressure in the stated ideal-solution model. Real mixtures and volatile solutes can depart from this approximation.
Worked example
Enter Solvent mole fraction: 0.8 1; Pure-solvent vapor pressure: 1000 Pa. Results: Estimated vapor pressure: 800 Pa.