Departure Functions: Example Problems

Try to solve these problems before watching the solutions in the screencasts.

Example Problem 1

A vapor with an ideal gas heat capacity of 45 J/mol-K is expanded across a well-insulated throttling valve. The vapor enters at 2.5 MPa and 600 K and exits at 0.10 MPa and 520 K. Using this information, evaluate the enthalpy departure function at the inlet conditions.

Example Problem 2

The entropy of a gas at 300°C and 30. bar is 25 J/mol-K. At 250°C and 1.0 bar, the gas is ideal and its entropy is 45 J/mol-K. What is the departure entropy at 300.°C and 30. bar? The ideal gas heat capacity of the gas is 30 J/mol-K.