Certified Hyperbaric Technologist Practice Test 2025 – Comprehensive Exam Prep

To understand why 79% nitrogen at 1 ATA is equivalent to 600.4 mmHg in partial pressure, we start with the concept of atmospheric pressure. At sea level, 1 ATA (atmospheric pressure) is equivalent to 760 mmHg.

To calculate the partial pressure of nitrogen, we use the percentage of nitrogen in the atmosphere, which is approximately 79%. The formula for partial pressure is given by:

Partial Pressure = Total Pressure × Fraction of the Gas

In this case, the total pressure at 1 ATA is 760 mmHg, and the fraction of nitrogen is 0.79 (or 79%). Therefore, the calculation is as follows:

Partial Pressure of Nitrogen = 760 mmHg × 0.79 = 600.4 mmHg

This result is significant because it allows us to ascertain how much nitrogen is exerting its own pressure within the total atmospheric pressure at sea level. If we were to look at the other options, they represent various percentages or values that do not align with the correct calculation of nitrogen's contribution at 1 ATA. Thus, the answer is indeed 600.4 mmHg of nitrogen, accurately reflecting the partial pressure exerted by nitrogen in the atmosphere at