Question

Air is a mixture of gases with the following mass percentage composition: 75.52% N2, 23.15% O2, 1.28% Ar, and 0.046% CO2 (a) What are the partial pressures of N2, O2, Ar, and CO2, when the total pressure is 1.100 atm? (b) Calculate the molar Gibbs energy of mixing of air at 25 °C assuming ideal-gas behavior. (c) Determine the molar enthalpy of mixing and the molar entropy of mixing for air at 1.100 atm and 25 °C.

5. (3 pts) Air is a mixture of gases with the following mass percentage composition: 75.52% N2, 23.15% O2, 1.28% Ar, and 0.046% CO2 (a) What are the partial pressures of N2, O2, Ar, and CO2, when the total pressure is 1.100 atm? (b) Calculate the molar Gibbs energy of mixing of air at 25 °C assuming ideal-gas behavior. (c) Determine the molar enthalpy of mixing and the molar entropy of mixing for air at 1.100 atm and 25 °C.

Answer 1

by 75.52 Ang = mole fraction of N2 = 75.52f 23:15 + 1-28+0.046 = 0·7552 NO2 = mole fraction of o2 = 23.15 76-52723.151.11% + 0.046 = 0.2315 Kar = mole fraction of Ar = 1.28 75.524 28.15+1-28 ↑ 0.046 = 0.0128 CO2 = mole haition of con 0.046 75.524 23.15 +1.28f 0.046 partial pressures p= NAP =0.00046 p = partial pressure PNZ = 0.7552 1.100 P- tolal pressure = 0831 am as Pol 0.2315 x 1.100 -0.2546 alm. Par = 0.0128 x 1.100 = 0.01408 atm Por = Corf 1:500 0.0004 6 X 1.Lor 5.06x10 4 aton Āunning molar gibbs energy of moing - RTZ dilniki = 8.314 x 2980 7552 1n 0.7552 +0.2315 ln 0.2315 at 0.0128 1n 0.0128 +0.000461n 8.00046] = 1511.53 Jul. man Ās miring - cf-1511.53) = -44 = 5:07 2jul mole' at - 2982 T A Il mixing = Alunut taimixing = -15 11:53 + 151153 c) 9