Reversible and Irreversible Expansion/Compression Processes: Example Problems 

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

Example Problem 1

An ideal gas expands from 10 bar and 250°C to 1.5 bar and 150°C. The expansion is irreversible and adiabatic. What is the change in enthalpy for 10 mol of gas? 

Example Problem 2

One mole of an ideal gas in a closed piston/cylinder is compressed from 300 K and 0.10 MPa to 0.8 MPa in an isothermal pathway.

Calculate ΔU, ΔH, Q, WEC.