Mr. Forester and Mr. Chavarin were cooking burgers at the Senior Picnic (this was pre-pandemic) and the propane grill ran out of fuel. When they went to change tanks they noticed that the "empty" tank was covered in ice, which seemed unusual for a sunny June day in Oceanside. Sure enough, the outside temperature was 25 degrees Celsius, while they tank was at -5. If the empty tank still had 0.75 mol of propane once it reached equilibrium (gauge reading 0 kPa) with the air (the barometer said 101.27 kPa that day) and the initial reading for the pressure gauge on the fuel cylinder was [400 + the last three digits of your ID] kPa, how many moles of propane had they burned so far? I don't know what this is asking me to do so if somebody can help me that'd be great.