Rate of Effusion Calculator

Rate of Effusion (Graham's Law)

Compare effusion rates using molar masses.

2026-05-06T10:07:27.256Z
g/mol
g/mol

Relative Rate (Rate₁ / Rate₂)

3.9841

Gas 1 effuses 3.98x faster than Gas 2

Rate₁ / Rate₂ = √(M₂ / M₁)

Graham's Law

Graham's law of effusion states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

How to use

Provide molar masses (g/mol) for two gases. The calculator returns the relative rate using √(M₂/M₁).

Example

H₂ (2.016 g/mol) vs O₂ (32.00 g/mol) → Rate₁/Rate₂ ≈ √(32/2.016) ≈ 3.99.

FAQs

Q: Are units important? A: Use consistent molar mass units (g/mol). Q: What if masses are equal? A: Ratio = 1.

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