(a) dS = - R (x1 ln(x1) + x2 ln(x2) + x3ln(x3) + x4ln(x4)
dS = - 8.314 J/mol K * (0.7552*ln(0.7552) + 0.2315*ln(0.2315) + 0.0128*ln(0.0128) + 0.00046*ln(0.00046))
dS = 5.07 J/mol K
(b) Assume we have a mixture of 100 mol of air. If we Ar and CO2 frozen, we lost:
1.28 + 0.046 moles = 1.326 moles
And we have now:
100 - 1.326 = 98.674 moles of air.
In this case, the new molar compositions are:
XN2 = 75.52 moles / 98.674 = 0.765
XO2 = 1- XN2 = 0.235
And the new entropy is:
dS = - R (x1 ln(x1) + x2 ln(x2)) = -8.314 J/mol L * (0.765*ln(0.765) + 0.235*ln(0.235))
dS = 4.53 J/mol K
The composition of air is approximately 75.52% N_2, 23.15% O_2, 1.28% Ar, and 0.046% CO_2. (a)...
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)...