Which law states that the total pressure of a mixture of gases is equal to the sum of the pressures of all the gases in that mixture?

The correct answer is based on Dalton's Law of Partial Pressures, which articulates that in a mixture of non-reacting gases, the total pressure exerted is the sum of the individual pressures exerted by each gas in the mixture, assuming they occupy the same volume and temperature. This principle is crucial in fields such as exercise physiology, where understanding gas exchanges in the respiratory system is essential for assessing how oxygen and carbon dioxide levels contribute to overall pressure dynamics in the lungs.

Dalton's Law is foundational in understanding how each gas behaves independently within a mixture, allowing for calculations of the composition of gases in various environments, whether in the laboratory or inside the human body during physical exertion. This knowledge can be pivotal when studying pulmonary function and performance during exercise, ensuring effective assessment and training.

The other laws mentioned, while important in their own right, focus on different aspects of gas behavior. Boyle's Law relates to pressure and volume at a constant temperature, Charles's Law focuses on temperature and volume at a constant pressure, and Avogadro's Law concerns the volume of gas and the amount of substance. However, none of these specifically addresses the total pressure of a gas mixture as effectively as Dalton's Law does.