Which of the following correctly describes pressure in a gas mixture according to Dalton's Law?

According to Dalton's Law of Partial Pressures, the pressure exerted by a gas mixture is equal to the sum of the partial pressures of the individual gases in that mixture. This means that each gas in the mixture contributes to the total pressure based on its own pressure when it occupies the same volume at the same temperature.

The concept behind this law is that each gas behaves independently of the others, assuming they are all ideal gases. Therefore, the total pressure is a straightforward addition of these individual contributions, reinforcing that choice reflects the fundamental principle of how pressures in gas mixtures are calculated.

The other choices do not accurately summarize Dalton's Law. While partial pressures may be lower than the total in certain conditions, that is not a defining characteristic of gas mixtures. The relationship between pressure, temperature, and volume is addressed by the gas laws, but not in a way that directly corresponds to Dalton’s Law. Lastly, there is no set maximum limit like 1 atm for total pressure in a gas mixture; it can exceed this value depending on the conditions and amount of each gas present.