What would the partial pressure of oxygen equal in an air mixture at a depth of 99 feet under water?
A) 159 x 4 or 636 mm Hg
B) 159 x 3 or 477 mm Hg
C) 159 x 2 or 318 mm Hg
D) 159 mm Hg

Question

Quizplus · Accepted Answer

At a depth of 99 feet underwater, the pressure increases by approximately 1 atmosphere every 33 feet. Therefore, at 99 feet, the pressure is about 4 atmospheres (1 atmosphere at the surface + 3 atmospheres from the water depth). Since the partial pressure of oxygen in air at the surface is approximately 159 mm Hg (21% of 760 mm Hg), at 99 feet under water, it would be 159 mm Hg x 4 = 636 mm Hg.

What Would the Partial Pressure of Oxygen Equal in an Air