Free Graham's Law Calculator

Calculate the ratio of effusion or diffusion rates of two gases using Graham's Law, based on their molar masses.

g/mol
g/mol

Rate₁ / Rate₂

4.0000

Rate₁ / Rate₂ vs Molar Mass of Gas 1

Graham's Law of Effusion

Formula

Rate₁ / Rate₂ = √(M₂ / M₁)

Where:

  • Rate₁, Rate₂ = effusion rates of gas 1 and gas 2
  • M₁, M₂ = molar masses of gas 1 and gas 2
  • Lighter gases effuse faster. The rate is inversely proportional to the square root of molar mass.

    Example Calculation

    Compare effusion rates of H₂ (2 g/mol) and O₂ (32 g/mol).

    1. 01Rate₁/Rate₂ = √(M₂/M₁)
    2. 02Rate₁/Rate₂ = √(32/2)
    3. 03Rate₁/Rate₂ = √16
    4. 04Rate₁/Rate₂ = 4.0
    5. 05H₂ effuses 4 times faster than O₂

    Frequently Asked Questions

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