Which law states that gas diffusion rate is inversely proportional to the square root of its molecular weight?

The correct choice is based on Graham's Law, which specifically addresses the behavior of gases in relation to their molecular weights. According to Graham's Law, the rate at which a gas will diffuse is indeed inversely proportional to the square root of its molecular weight. This means that lighter gases will diffuse faster than heavier gases. The relationship can be summarized mathematically, showing that if one gas has a lower molecular weight compared to another, it will diffuse more quickly in a given environment.

This principle is essential in respiratory care and various applications in medicine and science, as it explains how gases such as oxygen and carbon dioxide will behave differently in the context of diffusion across alveolar membranes or through other barriers. Understanding this concept helps in optimizing gas exchange in clinical and therapeutic situations.

Other laws mentioned, such as Henry's Law, deal with the solubility of gases in liquids, Bernoulli's Principle relates to fluid dynamics, and Poiseuille's Law pertains to the flow of viscous fluids in tubes. These principles, while important in their respective contexts, do not address the relationship between gas diffusion rates and molecular weights in the same way that Graham’s Law does.