How can the partial pressure of a gas be calculated?

The correct approach to calculating the partial pressure of a gas involves multiplying the total atmospheric pressure by the percentage of the gas present in the mixture. This relationship is derived from Dalton's Law of Partial Pressures, which 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. By determining the percentage concentration of the gas in the mixture and applying it to the total pressure, you can effectively calculate the partial pressure.

For instance, if the total pressure is 1 atmosphere and the gas makes up 20% of the mixture, the partial pressure of that gas would be calculated as 1 atm x 0.20, resulting in a partial pressure of 0.2 atm. This method is fundamental in both theoretical calculations and practical applications, such as in respiratory physiology or scuba diving, where understanding the partial pressures of different gases is crucial to prevent conditions like hypoxia or decompression sickness.