1. The problem statement, all variables and given/known data Calculate the work done by the system in an irreversible (single step) adiabatic expansion of 2 moles of a polyatomic gas ([itex]\gamma[/itex] = 4/3) from 300K and pressure 10 atm to 1 atm. 2. Relevant equations Work done in adiabatic process W = nCv[itex]\Delta[/itex]T n = Moles of gas Cv = R/([itex]\gamma[/itex]-1) R-Universal gas constant [itex]\Delta[/itex]T- Change in absolute temperature 3. The attempt at a solution The given answer is 405R. I am unable to find out the change in temperature as final temperature and volume are unknown. Is there any other formula to calculate the work done in adiabatic expansion?