1. The problem statement, all variables and given/known data Two 800 cm^3 containers hold identical amounts of a monatomic gas at 20 degrees C. Container A is rigid. Container B has a 100 cm^2 piston with a mass of 10 kg that can slide up and down vertically without friction. Both containers are placed on identical heaters and heated for equal amounts of time. Will the final temperature of the gas in A be greater than, less than, or equal to the final temperature of the gas in B? 2. Relevant equations I don't know if equations are necessary. 3. The attempt at a solution My professor attempted to cover 4 thermodynamics chapters in about 100 minutes. To say the least, he didn't do such a good job. I'm gonna assume I can ignore the part with the flame, since it's being applied to both cylinders. I know if you do work on the air molecules you can also increase the temperature. Question is though, since the piston moves up and down, does that imply its change in distance is 0 and in which case does it mean the amount of work it does = 0? Which further means its not increasing the temperature of the air molecules? Hence Temp (A) = Temp (B) ?