How would you estimate the number of gas molecules in one cubic meter of air in the classroom on an average day?

1 Answer
May 11, 2016

We would use the molar volume of an ideal gas at "SLC" as an approximation. There are are approx 41 moles of air, thus 41*molxxN_A = "number of gas molecules"

Explanation:

Given the molar volume, we know that 1 mole of an ideal gas occupies 24.5*L at "SLC", i.e. the molar volume is 24.5*L*mol^-1.

Knowing that 1 m^3 = 1000*L we simply divide this quantity by the first:

"Number of moles" = (1000*L)/(24.5*L*mol^-1) = 41*"moles"

Each mole of gas contains N_A gas molecules, whose behaviour is assumed to be ideal.

Thus, "number of gas molecules" 41*molxxN_A = 41*molxx6.022xx10^23*mol^-1 .