Hexane is throttled from 18.15 bar, 507.6 K to 0.1 bar. Determine the temperature at the exit and the entropy generation.
Steam is cooled under constant pressure from 400oC, 3 bar to a final state that contains wet steam with Xv = 0.9. (hint: for this problem it might be easier to use the Mollier diagram than the steam tables)
a. Determine ?H and ?S.
b. Determine the heat needed to increase Xv to 1.
3. A tank (V = 0.19 m3 ) full of cyclohexane and T = 554 K explodes at P = 20 bar. The final state of cyclohexane is a vapor at 1 bar.
a. What is the final temperature of the cyclohexane? The ideal gas, constant pressure heat capacity of cylcohexane is 200 J/mol/K.
How much energy was released in the explosion?
4. An insulated tank at 20 bar contains wet steam with 20% moisture. The tank is emptied by throttling its contents to the atmosphere, assumed to be at 1 bar. Assuming the entropy generation inside the tank is zero and the initial specific entropy inside the tank is Si, what is the entropy of the tank (in J/K) when it is half empty by mass?