A 5-m³ tank contains 2 kmol of oxygen and 5 kmol of nitrogen at 300 K.

a. Find the total pressure of the mixture.

b. Find the apparent constant-volume specific heat using a mass-basis  (c_v,mix in kJ/kg · K) and molar-basis (c_v,mix in kJ/kg · K).

c. Find the heat transfer required to raise the temperature of the mixture to 500 K using the apparent specific heat from part b. Assume that the apparent specific heat remains constant during this process.

d. Find the heat transfer required to raise the temperature of the mixture to 500 K using sensible enthalpy values, h̅° (T) - h̅°_f (198 k).