What characterizes gases based on their partial pressures in a mixture?

The correct choice highlights that partial pressure is directly proportional to the amount of each gas present in a mixture. This concept is rooted in Dalton's Law of Partial Pressures, which states that in a mixture of non-reacting gases, the total pressure exerted by the gas mixture is equal to the sum of the partial pressures of each individual gas.

In this context, the partial pressure of a specific gas is determined by its mole fraction in the mixture and the total pressure. Thus, if the amount (or number of moles) of a particular gas increases while the volume and temperature remain constant, its partial pressure will also increase proportionally. This relationship is crucial in various applications, including respiratory physiology and gas law calculations.

While other statements touch on properties of gases, they do not accurately capture the relationship between the amount of gas and its contribution to the total pressure. For example, stating that partial pressures are equal for all gases ignores the fact that different gases can occupy different volumes and contribute differently to total pressure based on their amounts. Additionally, the idea that partial pressure is independent of gas amounts is contrary to the very definition of partial pressure, which depends on the presence and quantity of gases. The mention of volume regarding proportionality without considering the