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the partial pressure of O2 in air is 158 mmHg at 25 degrees C and a total pressu

ID: 878083 • Letter: T

Question

the partial pressure of O2 in air is 158 mmHg at 25 degrees C and a total pressure of 760 mmHg. The air that is expired from your lungs after breathing has a partial pressure of O2 of 115 mmHg under the same conditions. How many moles of O2 are absorbed by your lungs from 1.0 L of air? 4. The partial pressure of O2 in air is 158 mmHg at 25°C and a total pressure of 760 mmHg. The air that is expired from your lungs after breathing has a partial pressure of 02 of 115 mmHg under the same conditions. How many moles of 02 are absorbed by your lungs from 1.0L of air?

Explanation / Answer

The solution is as shown below

pressure of O2 absorbed by lungs = 158 - 115 = 43 mmHg

total pressure = 760 mmHg

moles fraction of O2 = 43/760 = 0.057

total volume = 1.0 L

calculate total moles of O2,

n(total) = P(total) x V/RT

            = 1 atm x 1 L / 0.0821 x 298 K

            = 0.041 mols

moles of O2 = 0.057 x 0.041 = 0.0023 mols

Thus, 0.0023 mols of O2 is absorbed by lungs