What environmental conditions are necessary for Graham's ratio to maintain accuracy?

Graham's law, which describes the diffusion rates of gases, maintains its accuracy under normal air conditions, provided there is no depletion of oxygen. This is because the law is based on the principles of kinetic molecular theory, which operates under the assumption that gases behave ideally. In normal atmospheric conditions, the presence of oxygen is vital for maintaining stable diffusion rates among gases. If oxygen levels are significantly depleted, it can alter the behavior of the gas mixtures, making the application of Graham's law less reliable.

The law posits that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. In normal air, the interactions between gases such as nitrogen and oxygen remain predictable, allowing for accurate calculations based on the established ratios of molecular weights. Therefore, maintaining a standard atmospheric composition ensures that the foundational assumptions of Graham's law are upheld, allowing it to function accurately in its predictions and calculations.