Question

Atmospheric pressure at sea level is 760 mm Hg, and oxygen makes up 20.9% of this air when it is dry. Scientists at the Mt. Washington Observatory in New Hampshire measured the atmospheric pressure at the summit of Mt. Washington (6,289 feet above sea level) as 609 mm Hg. When the air is dry, the partial pressure of oxygen at the summit is approximately _____ mm Hg.

Answer 1

127.28 mmHg

Step-by-step explanation:

The molar fraction of oxygen in dry air at 760 mmHg is 20.9%. This molar fraction is not affected too much by the height, so it may be taken as a constant. The partial pressure of oxygen may be calculated as:

`P_{O_(2)}=y_{O_(2)}*P`

So, if the total pressure is 609 mmHg,

`P_{O_(2)}=0.209*609=127.28` mmHg.