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L - atms/ mol K calories/mol K 11, Use PV=nRT to calculate the moles of carbon d

ID: 695408 • Letter: L

Question

L - atms/ mol K calories/mol K 11, Use PV=nRT to calculate the moles of carbon dioxide gas that are present in a 100 mL flask at 3.5 atm pressure and a temperature of 60°C. 12. Without repeating your work in question 11, calculate the density of the gas under these conditions. 13. Without repeating your work in question 11, calculate the molar mass of the gas under these conditions. 14. A sample of gas is 51.4 mole% CH, 23.6 mole% N2, and the rest is Ar. a. What is the mole fraction of the Ar in the flask?

Explanation / Answer

11. Pressure,P=3.5 atm, Volume, V=0.100 L, Temperature, T=273+60=333 K
    R=0.08206 atm.l/atm.K,
    Number moles, n=(PV/RT)
                   =(3.5*0.100)/(0.08206*333)
                  n=0.013 moles
12.Equation for density of a gas, d=(PM/RT)
                           =(3.5 atm * 44 g/mol)/(0.08206 atm.L/mol.K * 333 K)
                 density,d = 5.63 g/L
13. Equation for the molar mass,
                               M = (dRT/P)
                                 = (5.63*0.08206*333)/(3.5)
                               M = 43.95 g/mole
14.Percent mole of Ar = 100-(51.4+23.6)
                      =25 %
Moles, CH4=51.4/100 = 0.514 moles
Moles, N2=23.6/100 = 0.236 moles
Moles, Ar=25/100 = 0.25 moles
Mole fraction of Ar = (0.25)/(0.514+0.236+0.25)
                         = 0.25