A mass less piston divides a thermally insulated cylinder into two parts having volumes V = 2.5 litre and 3 V = 7.5 litre. 0.1 mole of an ideal gas is confined into the part with volume V at a pressure of `P = 10^(5) N//m^(2)`. The other part of the cylinder is empty. The piston is now released and the gas expands to occupy the entire volume of the cylinder. Now the piston is pressed back to its initial position. Find final temperature of the gas.
[Take `R = (25)/(3) J mol^(-1) K^(-1)` and `gamma = 1.5` for the gas]

Answer

`600 K`