I'm working on a problem that says: A 4.00 gram sample of a mixture of CaO and BaO is placed in a 1.00 L vessel containing Co2 at a pressure of 730 torr and a temperature of 25C. The CO2 reacts with the CaO and BaO forming CaCO3 and BaCO3. When the reaction is complete, the pressure of the remaining Co2 is 150 torr.
a) Calculate the number of moles of Co2 that have reacted.
I already did this part and got 0.0312 moles CO2. I am stuck on the second part though.
b) Calculate the mass percentage of CaO in the mixture.
I know it will have something to do with grams of CaO = x and grams BaO = 4-x but I don't know how to solve from there. If anyone could please help that would be great thanks!