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

Answer:

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# .