How to use the dalton's law of partial pressures calculator
Find the partial pressure of each gas in a mixture. Enter total pressure, moles gas a, moles gas b in the fields above; the mole fraction of a, partial pressure of a, partial pressure of b are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- P — Total pressure (kPa)
- nA — Moles gas A (mol)
- nB — Moles gas B (mol)
Worked example
With total pressure = 101.3 kPa, moles gas a = 2 mol, moles gas b = 3 mol, the calculator gives mole fraction of a ≈ 0.4; partial pressure of a ≈ 40.52 kPa; partial pressure of b ≈ 60.78 kPa.
Frequently asked questions
What is the formula for the dalton's law of partial pressures calculation?
Mole fraction of A = nA / (nA+nB). Partial pressure of A (kPa) = P × [Mole fraction of A]. Partial pressure of B (kPa) = P-[Partial pressure of A]. Here P is total pressure (kPa), nA is moles gas a (mol), nB is moles gas b (mol).
What inputs do I need for the dalton's law of partial pressures calculator?
You need total pressure in kPa, moles gas a in mol, moles gas b in mol. 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.