An adult inhales about 6.0 x 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 x 10⁵ pa and the air is at a temperature of 300 k.
how many oxygen molecules are in each breath?
a. 1.4 x 10²³
b. 2.9 x 10²¹
c. 4.9 x 10⁻⁴
d. 2.9 x 10²⁵

B.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number of particles.

Given : Volume of fresh air =

volume of oxygen  =

According to the ideal gas equation:

P = Pressure of the gas =  = 0.98 atm

V= Volume of the gas =  

T= Temperature of the gas = 300 K      

R= Gas constant = 0.0821 atmL/K mol

n=  moles of gas= ?

1 mole of oxygen contains = molecules

Thus  of oxygen contain= molecules of oxygen  

Thus there are oxygen molecules in each breath