3. Air is contained within a piston-cylinder assembly The cross sectional area of the piston is 0.01 m². Initially the piston is at 1 bar and 25°C, 10 cm above the base of the cylinder. In this state, the spring exerts no force on the piston. The system is then reversibly heated to 100°C. As the spring is compressed, it exerts a force on the piston according to: F=-kx where k= 50,000 N/m and x is the displacement length from its uncompressed position. Determine the work done.

Using 1st and 2nd law of thermodynamics for irreversible expansion of Krypton: Krypton (ideal monatomic gas) is confined in one-fourth of a 48-litre container. The other part of the container is evacuated. When the partition is removed, the gas expands and fills the whole container, while the system loses 400J of heat to the environment at 290K. It is found that in the final state, the Krypton is at p2 = 5.5bar, T2 = 400K. Is this process possible or not? (?k?????? = 83.8 kg/kmol)