Graham's Law Diffusion Coefficient Calculator

Calculates diffusion coefficient from solubility coefficient and gram molecular weight.

Inputs

Color mode links each input to the matching equation term and solving arithmetic.

Equation and Work

Equation:
Solving steps:
Diffusion coefficient
—
relative
√gmw
—
value
Reference
—
note

Clinical Significance

Graham’s law states that diffusion is inversely proportional to the square root of gram molecular weight. The respiratory-care coefficient uses solubility divided by √gmw.

The equation helps compare gas diffusion behavior; for example, CO₂ has a much higher diffusion coefficient than O₂.

This is a gas property calculation. Patient oxygenation also depends on surface area, membrane thickness, and pressure gradients.

References (APA 7th Edition)

  1. Chang, D. W. (2020). Respiratory Care Calculations (Revised 4th ed.). Jones & Bartlett Learning. Formula content adapted from the uploaded text/reference packet.