What this calculator does
Raoult’s law (vapor pressure of a solution) works out vapor pressure of an ideal solution containing a non-volatile solute. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaPsolution = Xsolvent · P°solvent
The inputs explained
| Field | What to enter |
|---|---|
| Moles of solute | A number. Starts at 1. |
| Moles of solvent | A number. Starts at 50. |
| Vapor pressure of pure solvent (mmHg) | A number, measured in mmHg. Starts at 23.8. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with moles of solute
Every other input is held at the calculator’s starting values while moles of solute varies. Select any row to load that scenario into the calculator.
How the answer changes with moles of solute