According to Dalton's Law of Partial Pressures, what is total pressure composed of?

Dalton's Law of Partial Pressures states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of each individual gas within the mixture. Each gas in the mixture exerts pressure independently of the others, and the total pressure is obtained by simply adding these individual pressures together.

This principle helps in understanding gas behavior in various situations, such as in respiratory physiology and in various engineering applications. The partial pressure of a gas is defined as the pressure that the gas would exert if it occupied the entire volume alone at the same temperature. This law applies regardless of the types or amounts of gases present, as long as they do not react with one another.

In contrast, the other options do not accurately represent the relationship of pressures in a gas mixture as defined by Dalton's Law. The combination of the partial pressures fundamentally captures the essence of how different gases contribute to the overall pressure in a mixture, making the answer about the sum of the partial pressures of the component gases the correct choice.