A mixture of ideal gases has the following composition by mass :Oxygen(60%), Carbon dioxide(20%),Nitrogen(20%)Calculate the Characteristic gas constant of the mixture in J/kg-K.

Oxygen is contained in a cylinder at a pressure of 95 bar and a temperature of 185.52 K. Estimate the molar volume in units ?^3/??? and the specific volume in units ?^3/?? using : (a) The ideal gas equation of state (b) Van der Waals equation of state (c) Redlich-Kwong equation of state (d) Lee Kesler correlation Argue why oxygen is a real gas under these conditions. Evaluate the accuracy of each correlation.

6) Calculate the absolute entropy for 1 mole of Ar gas (monatomic) with 22.4 liter volume at 273 K using Boltzmann's formula. What is the change in entropy if the temperature doubles while V is constant? What is the change in entropy if the volume doubles while T is constant? What is the change in entropy if both T and V double? (Note: To evaluate In(N!) use Stirling's asymptotic formula In(N!) ~ N In N – N ) S-k log W LVDWIG BOLTZMANN 18W-1906 DE FHILPAULA BOLTZMANN GER CAR

13 An ideal solution of 5.25 moles of benzene and 3.0 moles of toluene is placed in a piston and cylinder assembly. At 298 K, the vapor pressure of pure substances are P°(benzene) = 96.4 torr & P°(toluene) = 28.9 torr. The vapor pressure of the solution is; 69.81 torr O 71.83 torr 53.47 torr O 66.61 torr 67.50 torr