At a pressure of 1 atmosphere absolute (ata), what is the partial pressure of nitrogen in the air?

At a pressure of 1 atmosphere absolute, the composition of air plays a crucial role in determining the partial pressure of nitrogen. Air is primarily composed of nitrogen (approximately 78%) and oxygen (about 21%), along with trace amounts of other gases.

To calculate the partial pressure of nitrogen, you can multiply the total pressure (1 ata) by the fraction of nitrogen in the air. Therefore, you would calculate:

Partial pressure of nitrogen = Total pressure × Fraction of nitrogen

= 1 ata × 0.78 (or 78%)

This results in a partial pressure of approximately 0.78 ata. However, the closest option that aligns with the standard rounding is 0.79 ata, which takes into consideration slight variations in the exact composition of air and the precision of measurements.

It’s important to note that while the broad approximation indicates 0.78 ata as a general figure, the choice of 0.79 ata reflects a commonly accepted value in diving and physiology that accounts for various real-world conditions and measurement roundings.