The air exhaled by an average human being might have the following typical combustion, expressed in terms of partial pressures: N2 = 569torr; O2 = 116 torr; CO2 =28 torr; water vapor = 47 torr. what are the mole fractions of each?
Ptotal = pN2 + pO2 + pCO2 + pH2O
XN2 = pN2/ptotal
XO2 = pO2/ptotal
etc.