Question

"how many molecules of carbon dioxide exit your lungs when you exhale 5.00 × 10−2 mol of carbon dioxide, co2?"

Answer 1

We are going to use Avogadro's constant to calculate how many molecules of

carbons dioxide exist in lungs:

when 1 mole of CO2 has 6.02 x 10^23 molecules, so how many molecules in

CO2 when the number of moles is 5 x 10^-2

number of molecules = moles of CO2 * Avogadro's number

                                     = 5 x 10^-2  * 6.02 x 10^23

                                     = 3 x 10^22 molecules 

∴ There are 3 x 10^22 molecules in CO2 exist in lungs 

Answer 2

The number of CO2  molecules  that   exit  is calculated   as   follows

by use  of Avogadro   law  constant

1   mole  = 6.02 x10^23  molecules
5.00 x10^-2 mol   =?   molecules

{( 6.02  x10^23)x (5.00  x10^-2) / 1}  = 3.01 x10^22  molecules