What is Dalton’s Law of Partial Pressures?

Dalton’s Law, formulated by John Dalton in 1801, states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. This principle is fundamental in chemistry and physics, particularly when studying thermodynamics and atmospheric sciences.

The Formula

The mathematical representation of Dalton's Law is straightforward:

P_total = P₁ + P₂ + P₃ + ... + P_n

Where P_total is the total pressure of the container and P_n represents the partial pressure of each individual gas component.

How to Use This Calculator

Using our Dalton’s Law Calculator is simple and efficient:

1. Input Pressures: Enter the known partial pressures in the input fields provided.
2. Add More Gases: If your mixture contains more than two gases, click the "Add Gas" button to create more input rows.
3. Calculate: Click the calculate button to see the total pressure.
4. Review Steps: The calculator will provide a detailed step-by-step breakdown of the summation process.

Frequently Asked Questions

Does the type of gas matter in Dalton's Law?

No, Dalton's Law assumes the gases behave ideally and do not react with one another. The identity of the gas molecules does not affect the total pressure; only the number of molecules and their kinetic energy (temperature) matter.

What units should I use?

You can use any unit of pressure (atm, kPa, mmHg, PSI), provided that all inputs use the same unit. The resulting total pressure will be in that same unit.

When does Dalton's Law fail?

Dalton's Law is most accurate for ideal gases at low pressures and high temperatures. It may deviate at very high pressures where intermolecular forces between gas particles become significant.