If 20 percent of the air is composed of O₂, what is the partial pressure of oxygen at an altitude of 20000 feet, where atmospheric pressure is 350 mmHg
A)20 mmHg
B)70 mmHg
C)152 mmHg
D)760 mmHg

Question

Quizplus · Accepted Answer

The partial pressure of oxygen can be calculated by multiplying the total atmospheric pressure by the fraction of oxygen in the air. At 20,000 feet, the atmospheric pressure is 350 mmHg, and oxygen makes up 20% (or 0.20) of the air. Therefore, the partial pressure of oxygen is 350 mmHg * 0.20 = 70 mmHg.

If 20 Percent of the Air Is Composed of O₂