One kmol of ideal gas (Cp=30 j/mol*k) is contained in a piston cylinder initially at 25C and 10bar. The mass of the piston is 500kg and it is held in place by a latch. The surroundings are @25C and 1 atm. The latch is removed and the piston oscillates a few times and comes to rest. Heat is trtansferred to the gas so that the final temperature of the ideal gas is 25C. Calculate the amount of heat transferred and prove this process is reversible (or not) by calculating entropy.