5.00 g H2 and 10.0 g O2 are combined in a 10.0 L container at 25°C and then ignited. Calculate the final pressure in the container. You must compare the pressure the water would have if it all existed as vapor to the vapor pressure of water at that temperature! If greater it condenses to have the equilibrium vapor pressure.

Answer 1

MgCO3 --> MgO + CO2
1.00kg MgCO3 x 10^3g/1kg x 1 mol MgCO3/84.32g MgCO3 x 1 mol CO2/1 mol MgCO3 = 11.860 mol CO2

PV=nRT
V = nRT/P = 11.860 mol x 0.08206 Latm/molK x 632K / 1.00 atm = 606.32L

1.00kg MgCO3 x 10^3g/1kg x 1 mol MgCO3/84.32g MgCO3 x 1 mol CO2/1 mol MgCO3 x 44.01g CO2/1 mol CO2 = 522g CO2

522g/606.32L = 861 g/mL

Answer 2

Sorry i posted the answer to a different question:

What volume of carbon dioxide would be produced at 350˚C and
1.00 atm from the complete thermal decomposition of 1.00 kg of
magnesium carbonate, MgCO3? What is the density of carbon dioxide
at this temperature?