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Referring to the table that follows,
Gas Composition (% by volume) of Air
N2 78.03
O2 20.99
Ar 0.94
CO2 0.033
Ne 0.0015
He 0.000524
Kr 0.00014
Xe 0.000006
a) Calculate the mol fraction of CO2
(b) Calculate the parts per million (ppm) by volume of CO2.
Expert Answer
If this is composition by volume, then assume T is the same for all, so we can apply Avogrados law; which relates volume to moles
therefore…
% of CO2 = 0.033; then volume fraction is acutally = 0.033/100 = 0.00033
mol fraction = volume fraction
so
mol fraction = 0.00033
b)
ppm is given by = microL of CO2 / L of gas
assume a basis of 1 liter of gas
0.00033*1 = 0.00033 liters of CO2 = 0.00033*10^6 mL of CO2 = 330 microL
recalculate ppm;:
ppm = 330 mcroiL / L = 330 ppm of CO2
