What this calculator does
Partial pressure (Dalton's law) works out partial pressure of each gas in a mixture from its moles, volume and temperature. 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
FormulaPᵢ = nᵢRT/V; Ptotal = ΣPᵢ (Dalton's law of partial pressures), R = 0.0820574 L·atm/(mol·K)
The inputs explained
| Field | What to enter |
|---|---|
| Moles of each gas, mol (comma-separated) | A list of numbers, separated by commas or spaces. |
| Temperature (K) | A number, measured in K. Starts at 298.15. |
| Container volume (L) | A number, measured in L. Starts at 10. |
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 temperature
Every other input is held at the calculator’s starting values while temperature varies. Select any row to load that scenario into the calculator.
How the answer changes with temperature
| Temperature (K) | Total pressure | Total moles | Gas constant R used |
|---|---|---|---|
| 149 | 2.445 atm | 2.000 mol | 0.082057 L·atm/(mol·K) |
| 224 | 3.676 atm | 2.000 mol | 0.082057 L·atm/(mol·K) |
| 298 | 4.891 atm | 2.000 mol | 0.082057 L·atm/(mol·K) |
| 447 | 7.336 atm | 2.000 mol | 0.082057 L·atm/(mol·K) |
| 596 | 9.781 atm | 2.000 mol | 0.082057 L·atm/(mol·K) |
| 894 | 14.672 atm | 2.000 mol | 0.082057 L·atm/(mol·K) |