Partial Pressure Calculator

Partial Pressure Calculator

Compute mole fractions and partial pressures (Dalton's law).

2026-05-06T10:07:27.251Z
atm
Gas 1
Gas 2

Gas 1

0.5000 atm

Mole Fraction (χ)

0.5000

Gas 2

0.5000 atm

Mole Fraction (χ)

0.5000

P_i = χ_i × P_total

Dalton's Law of Partial Pressures

Dalton's law states that in a mixture of non-reacting gases, the total pressure is the sum of the individual partial pressures: P_total = ΣP_i.

How to use

Enter the total pressure and the mole amount for each gas component. The calculator shows each component's mole fraction and partial pressure.

Example

If you have 1 mol of A and 3 mol of B at 1 atm total, χ_A = 0.25 → P_A = 0.25 atm; χ_B = 0.75 → P_B = 0.75 atm.

FAQs

Q: Can mole fractions exceed 1? A: No, fractions sum to 1. Q: Units? A: Pressure in atm, mole counts in moles (unitless fractions).

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