The residual enthalpy of saturated CO2, as calculated from the SRK equation of sate, is given below

The ideal gas heat capacity of carbon dioxide is  = 33 J/mol/K and can be assumed to be independent of temperature.

a. Calculate the enthalpy of the saturated liquid and saturated vapor at 230 K and 245 K using the information in the above table. The reference state is the saturated liquid at 245 K.

b. A stream containing saturated liquid CO₂ is throttled from 245 K to 11.6 bar. Calculate the fraction of vapor at the exit of the throttling valve.

c. After the throttling valve, the CO₂ is passed through a heat exchanger from which it exits as saturated vapor.  Calculate the amount of heat.

d. Calculate the entropy change of CO2 in the heat exchanger.