Question

There are 602 sextillion, or 602,000,000,000,000,000,000,000, gas molecules in 1 mole.

Calculate the number of gas molecules in a breath at sea level. Calculate the number of
gas
molecules in a breath on a mountaintop. (Show your work.)

Answer 1

The average breath volume of an adult is about 500 mL at sea level and about 350 mL on a mountaintop.

At sea level:

Number of moles in one breath = volume of breath in liters/22.4 L/mol

Number of moles in one breath = 0.0005 L / 22.4 L/mol

Number of moles in one breath ≈ 0.00002 mol

Number of gas molecules in one breath = number of moles x Avogadro's number

Number of gas molecules in one breath = 0.00002 mol x 6.02 x 10^23/mol

Number of gas molecules in one breath ≈ 1.2 x 10^19 gas molecules

On a mountaintop:

Number of moles in one breath = volume of breath in liters/22.4 L/mol

Number of moles in one breath = 0.00035 L / 22.4 L/mol

Number of moles in one breath ≈ 0.000016 mol

Number of gas molecules in one breath = number of moles x Avogadro's number

Number of gas molecules in one breath = 0.000016 mol x 6.02 x 10^23/mol

Number of gas molecules in one breath ≈ 9.6 x 10^15 gas molecules