What are the moles of CO2, mass percent CaO, and percent of BaO?

Question

A mixture of solid calcium oxide, CaO,CaO, and solid barium oxide, BaO,BaO, weighing 3.918 g3.918 g is added to a 2.00 L2.00 L flask containing carbon dioxide, CO2,CO2, at 30 ∘C.30 ∘C. The CaOCaO and BaOBaO react completely with the carbon dioxide gas to form solid CaCO3CaCO3 and BaCO3,BaCO3, respectively. Calculate the moles of CO2CO2 consumed by the reaction if the initial pressure of CO2CO2 gas was 0.731 atm0.731 atm and the final pressure of CO2CO2 gas is 0.220 atm.0.220 atm.

moles of CO2:CO2:

What is the mass percentage of CaOCaO in the solid mixture?

mass percent CaO:CaO:

What is the mass percentage of BaOBaO in the solid mixture?

mass percent BaO:BaO:

Answer 1

Change in pressure = 0.731 atm - 0.220 atm = 0.510 atm

Converting this to moles of CO₂ using the ideal gas law, we have...

PV = nRT

n = moles = PV/RT = (0.510 atm)(2.00 L) / (0.0821 Latm/Kmol)(303K)

n = 0.0410 moles CO₂ used

molar mass CaO = 56.1 g / mol

molar mass BaO = 153 g / mol

CaO + BaO + 2CO₂ ==> CaCO₃ + BaCO₃

mole ratio of CaO : BaO in balanced equation is 1:1

153 / 56.1 = 2.733 : 1

Total = 2.733 + 1.000 = 3.733

mass %CaO = 1.000 / 3.737 (x100%) = 26.79%

mass %BaO = 2.733 / 3.733 (x100%) = 73.21%