An ore contains Fe3O4 and no other iron. The
iron in a 59.51 gram sample of the ore is all
converted by a series of chemical reactions to
Fe2O3. The mass of Fe2O3 is measured to be
33.8 grams. What was the percent Fe3O4 in
the sample of ore?
Answer in units of %
A 23.9475 g sample of impure magnesium carbonate 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 18.345 g. Assuming
that only the magnesium carbonate had decomposed, how much magnesium carbonate
was present in the original sample?
Answer in units of g
iron in a 59.51 gram sample of the ore is all
converted by a series of chemical reactions to
Fe2O3. The mass of Fe2O3 is measured to be
33.8 grams. What was the percent Fe3O4 in
the sample of ore?
Answer in units of %
A 23.9475 g sample of impure magnesium carbonate 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 18.345 g. Assuming
that only the magnesium carbonate had decomposed, how much magnesium carbonate
was present in the original sample?
Answer in units of g
-
2 Fe3O4 + ... → 3 Fe2O3 + ...
(33.8 g Fe2O3) / (159.6887 g Fe2O3/mol) x (2/3) x (231.5333 g Fe3O4/mol) /
(59.51 g) = 0.549 = 54.9%
MgCO3 → MgO + CO2
All of the weight lost was due to the evolution of CO2.
(23.9475 g - 18.345 g) / (44.00964 g CO2/mol) x (1/1) x (84.31413 g MgCO3/mol) = 10.733 g MgCO3
(33.8 g Fe2O3) / (159.6887 g Fe2O3/mol) x (2/3) x (231.5333 g Fe3O4/mol) /
(59.51 g) = 0.549 = 54.9%
MgCO3 → MgO + CO2
All of the weight lost was due to the evolution of CO2.
(23.9475 g - 18.345 g) / (44.00964 g CO2/mol) x (1/1) x (84.31413 g MgCO3/mol) = 10.733 g MgCO3