A thermally insulated cylinder, closed at both ends, is fitted with a frictionless heat conducting piston that divides the cylinder into two parts. Initially, the piston is clamped in the center with 1 liter of air at 300 K and 2 atm pressure on one side and 1 liter of air at 300 K at 1 atm pressure on the other side.
The piston is released and reaches equilibrium in pressure and temperature at a new position.
Compute the final pressure and temperature and increase of entropy if air is assumed to be the ideal gas. What irreversible process has taken place?