1. The problem statement, all variables and given/known data When 0.40 mol of oxygen(O2) gas is heated at constant pressure starting at 0 degrees C, how much energy must be added to the gas as heat to triple its volume? (The molecules rotate but do not oscillate) 2. Relevant equations pV=nRT p1V1/T1=p2V2/T2 Q=mcdT Value of Cp for Oxygen I used is 0.919 kJ/kg K 3. The attempt at a solution I used the equation pV=nRT to get the value of pV at 273K which was pV=907.5. I tripled that value to get 2722.5. Then, using p1V1/T1=p2V2/T2, I plugged in the values to get the final temperature(819K). From that I used Q=mcdT which gave me the answer of 3211kJ. The answer in the back was 6.4 kJ.