Question

Kevin first notices Nitrogen Narcosis when he is breathing air at a depth of about 80 fsw/24.4m. What is the partial pressure of Nitrogen (PN₂) in the air he inhales at this depth?

1) 1.9 ata/bar
2) 2.7 ata/bar
3) 2.9 ata/bar
4) 3.4 ata/bar
5) none of the above

Answer 1

The partial pressure of Nitrogen (PN₂) that Kevin notices at a depth of about 80 fsw/24.4m is found by multiplying the total pressure at that depth (3.44 atm) by the percentage of nitrogen in air (78%), resulting in a partial pressure approximately 2.6832 atm, with the closest answer being Option 3: 2.9 ata/bar.

Step-by-step explanation:

To determine the partial pressure of Nitrogen (PN₂) that Kevin notices at a depth of about 80 fsw/24.4m, a calculation based on the depth and the percentage of nitrogen in the air needs to be done. The ambient pressure at this depth can be found by using the formula:

Total pressure = 1 atm + (depth in meters × 0.1 atm/m)
At 24.4 m, the total pressure is 1 atm + (24.4 × 0.1 atm/m) = 3.44 atm.

The air that Kevin breathes is composed of approximately 78% nitrogen. Therefore, the partial pressure of nitrogen is calculated by multiplying the total pressure by the percentage of nitrogen:

PN₂ = Total pressure × percentage of nitrogen
PN₂ = 3.44 atm × 0.78 = 2.6832 atm.

The closest answer to the calculated partial pressure (without rounding off) is Option 3: 2.9 ata/bar, making it the correct choice.