Atmospheric pressure at sea level is equal to a column of 760 mm Hg. Oxygen makes up 21% of the atmosphere by volume. The partial pressure of oxygen (PO2) in such conditions is

Question

Quizplus · Accepted Answer

The atmospheric pressure at sea level is 760 mm Hg, and oxygen makes up 21% of the atmosphere by volume. Therefore, the partial pressure of oxygen (PO2) can be calculated as follows: 
PO2 = Atmospheric pressure x Fraction of oxygen 
= 760 mm Hg x 0.21 
= 159.6 mm Hg (rounded to 160 mm Hg) 
Therefore, the correct answer is A.

Atmospheric Pressure at Sea Level Is Equal to a Column