Final answer:
Gases consumed in chemical reactions do not contribute to the partial pressure that drives diffusion; false. Partial pressure is a measure of the concentration of a gas in a mixture, and only the remaining gases contribute to this pressure.
Step-by-step explanation:
The statement that gases used up in chemical reactions still contribute to the partial pressure, which helps drive diffusion, is false. Gases that have been consumed in a chemical reaction no longer contribute to the partial pressure in a gas mixture. Partial pressure is defined as the pressure exerted by a particular gas within a mixture of gases and is a measure of that gas's concentration. According to Dalton's Law of Partial Pressures, the total pressure exerted by a mixture of gases is the sum of the partial pressures of each component gas present in the mixture. Therefore, if a gas is used up in a reaction, it no longer exerts pressure in the system. Moving along a pressure gradient from an area of higher partial pressure to one of lower partial pressure is how gas diffusion occurs, as gases seek to equalize pressure across regions.