Graham's Law Diffusion Rate Calculator

Graham's Law Diffusion Rate Calculator

Lighter gas molecules move faster at a given temperature, and that speed difference translates directly into how fast different gases diffuse or effuse through small openings.

Formula: rate₁/rate₂ = √(M₂/M₁)

Example: helium (4.0 g/mol) versus nitrogen (28.01 g/mol): rate ratio = √(28.01/4.0) ≈ 2.65 - helium diffuses about 2.65 times faster than nitrogen.

How to Use This Calculator

1. Enter the molar mass of gas 1.
2. Enter the molar mass of gas 2.

This is exactly why a helium-filled balloon deflates noticeably faster than an air-filled balloon of the same material - helium's much smaller, lighter molecules escape through microscopic pores in the balloon material considerably faster.