Determine the reference state for the entropy and enthalpy of R134a chosen for the model implemented in STANMIX by inspecting the thermodynamic T ?? s or P ? h diagram in Appendix A. Determine the value of the internal energy of R134a at 410 K and 0.5 MPa if one datum state were the enthalpy of R134a of saturated vapor at T = 220 K. What would be the value of the enthalpy at this point?

Transcribed Image Text:

Fluid Argon Hydrogen Nitrogen Oxygen Carbon Water (liquid) Carbon monoxide Carbon dioxide Ammonia Methane Ethane Propane n-Butane Acetylene Benzene (liquid) Chemical formula Ar H₂ N₂ 0₂ C H₂O CO CO₂ NH3 CHA C₂ H₂ C3 Hg C4H10 C₂ H₂ C₂H₂ M/ kg/kmol 39.948 2.016 28.013 31.999 12.011 18.015 28.010 44.010 17.031 16.043 30.069 44.096 58.123 26.038 78.113 R/ J/(kg. K) 208.1 4124.7 296.8 259.8 692.2 461.5 296.8 188.9 488.2 518.3 276.5 188.6 143.0 319.3 106.4 Cp / J/mol K 20.786 28.836 29.124 29.378 8.540 75.300 29.141 37.135 35.630 35.695 52.487 73.597 99.167 44.036 135.950 2⁰/ kJ/mol 0 0 0 0 0 -285.830 -110.530 -393.510 -45.940 -74.600 -84.000 -103.847 -124.727 227.400 49.080 30/ J/(mol. K) 154.845 130.680 191.608 205.148 5.694 69.950 197.658 213.783 192.768 186.369 229.161 270.313 310.030 200.927 173.450