A balloon filled with 1.35 atm of dimethyl ether gas and 5.25 atm of oxygen gas at 27 °C has an initial volume 2.00L They react according to the following reaction: C2H6O (g) + 3 O2 (g) -> 2 CO2 (g) + 3 H2O (g) The system is allowed to back cool down to 27 °C following the reaction. Assuming the external pressure is still the same (6.60 atm), what is the new volume of the balloon? What is the partial pressure of carbon dioxide in the balloon?
I tried P1V1/T1=P2V2/T2 but the volume still comes out to 2. Does that mean the volume does not change since the system was allowed to cool to the original temperature? Help much appreciated!
1 answer
I don't think it means that. I think the fallacy in your thinking is that you've not taken into account the change in the number of mols during the reaction. I think you must convert pether and pO2 to mols using PV = nRT, determine the limiting reagent (which I think is the ether) calculate mols remaining of each material after equilibrium, and use those new mols numbers to solve for new volume and then pCO2.