What is the partial pressure of a gas calculated from?

The correct choice for calculating the partial pressure of a gas is derived from the relationship between total pressure and the mole fraction of the gas in the mixture. According to Dalton's Law of Partial Pressures, the partial pressure of a gas can be calculated by multiplying the total pressure of the gas mixture by the mole fraction of the individual gas within that mixture.

Mole fraction is defined as the ratio of the number of moles of a specific gas to the total number of moles of all gases present in the mixture. Thus, when you multiply the total pressure by the mole fraction, you effectively isolate the contribution of that specific gas to the overall pressure, leading to its partial pressure.

This concept is foundational in gas behavior and is widely utilized in various engineering applications, especially in chemical processing and reactor design, where understanding the individual gas contributions to the overall system pressure is essential for effective process control and analysis.

The other options do not correctly relate to the calculation of partial pressure. Density and volume do not directly provide the necessary components to establish a gas's partial pressure without additional information. Temperature and total pressure would offer some insights into gas behavior but are not sufficient to isolate a specific gas's contribution. Similarly, mass flow rate and total pressure concern mass transfer