1. The problem statement, all variables and given/known data Sulfur dioxide gas reacts with oxygen to produce sulfur trioxide gas. Two 2 liter flasks at 25 degrees Celsius are connected by a stopcock. One flask contains 100 grams of sulfur dioxide, and the other with oxygen to a pressure of 5 atm. When the stopcock is opened the gases react until one is completely consumed. What will be the final pressure of the system after the reaction is completed. 2. Relevant equations PV=nRT 3. The attempt at a solution I started with the balanced equation: SO2 (g) + O2 (g) = SO3 (g). I then used stoichiometry to calculate the number of moles of SO2 in the first flask, and then calculated the number of moles of O2 in the second flask using PV=nRT. I'm pretty sure that this first part is right, but if not please advise me on what to do. After this is what I'm unsure of what to do. I wasn't sure if I was supposed to find the pressure of the sum of the number of moles of the two gases using PV=nRT or to subtract the smaller number of moles of O2 gas from the larger number of moles from the SO2 gas and then use PV=nRT (because the problem statement says that one gas will be completely consumed).