A 28.4288 g sample of impure magnesium car-

Question

bonate was heated to complete decomposition
according to the equation
MgCO3(s) ! MgO(s) + CO2(g) .
After the reaction was complete, the solid
residue (consisting of MgO and the original
impurities) had a mass of 16.0467 g. Assum-
ing that only the magnesium carbonate had
decomposed, how much magnesium carbon-
ate was present in the original sample?
Answer in units of g
008 10.0 points
The reaction of 8.2 grams of fl

Answer 1

MgCO3 ==> MgO + CO2
loss in mass = mass CO2
Convert mass CO2 to mass MgCO3.
mass CO2 x (molar mass MgCO3/molar mass CO2) = mass MgCO3 in grams.