Question

9 Air a mixture is approximately 0.039% CO2 a Determine the partial pressure of CO2, in mm Hg, if the total atmospheric pressure is 760 mm Hg. This is the partial pressure of CO; breathed into the lungs.

Answer 1

More often than not, you will see partial pressen of gas being expressed in terms of mole fraction gas Xges x P mixture Also no- of moles = no. of molecules XNA Now the % composition of a gaseous mixture lls you how many molecules each gas contributes in 10o molecules of mixture In this case, air is said to be 0.039 % Co. This means that in every 100 molecules of air 0.039 will be co molecules no = 0.039X NA = 0.039NA The total number of moles in sample of air will be . then Qoz o nda nTotal = 100 molecules X NA = 100. NA The mole fraction of cog in mixture will be Xco, a 0.039 NA 0.00039 .. ALONA alco 0.00039 X 760 mmHg - 0.29 64 mm Hg which is approx 0.3 mm Hg