An adult inhales about 6.0×10−4 m3 of fresh air during a breath. only 20% of fresh air is oxygen. assume the pressure in the lungs is 1.0×105 paand the air is at a temperature of 300 k. how many oxygen molecules are in each breath? a. 1.4x10^23b. 2.9x10^21c. 4.9x10^-4d. 2.9 x10^25

B. 2.9X10^21

Explanation:

The volume of air inside a breath is

Of this, only 20% is oxygen, so the volume of oxygen is

Then we can find the number of moles of oxygen by using the ideal gas equation

where we have

is the gas pressure

is the oxygen volume

n is the number of moles of oxygen

is the gas constant

T = 300 K is the temperature

Solving for n, we find

Since the number of molecules in 1 mol is

(Avogadro number)

Then the number fo molecules in of oxygen is

an obstruction