Final answer:
The driving force for the movement of an individual gas within a mixture is the partial pressure of that gas. Gases tend to move from an area of higher partial pressure to an area of lower partial pressure, and the greater the partial pressure difference, the faster the movement.
Step-by-step explanation:
The driving force for the movement of an individual gas within a mixture is ultimately the partial pressure of that gas. In a gas mixture, each component has its own pressure, known as the partial pressure. This partial pressure determines the direction and rate of movement of the gas. Gases tend to move from an area of higher partial pressure to an area of lower partial pressure, and the greater the partial pressure difference, the faster the movement.