How to use the raoult's law calculator
Find vapor pressure of a solution. Enter mole fraction of solvent, pure solvent vapor pressure in the fields above; the solution vapor pressure, pressure lowering are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- x — Mole fraction of solvent
- P0 — Pure solvent vapor pressure (kPa)
Worked example
With mole fraction of solvent = 0.9, pure solvent vapor pressure = 3.17 kPa, the calculator gives solution vapor pressure ≈ 2.853 kPa; pressure lowering ≈ 0.317 kPa.
Frequently asked questions
What is the formula for the raoult's law calculation?
Solution vapor pressure (kPa) = x × P0. Pressure lowering (kPa) = P0-[Solution vapor pressure]. Here x is mole fraction of solvent, P0 is pure solvent vapor pressure (kPa).
What inputs do I need for the raoult's law calculator?
You need mole fraction of solvent, pure solvent vapor pressure in kPa. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.