Sorry about the repost, but I am frustrated with this problem. An ideal monatomic gas, consisting of 2.47 mol of volume 0.0890 m3, expands adiabatically. The initial and final temperatures are 22.3oC and -64.3oC. What is the final volume of the gas? I've tried solving for P in terms of T using PV = nRT and it didn't seem to work out. Am I even starting in the right place?