Stoichiometry worksheet with answers

Free printable Stoichiometry worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
m(Fe2​O3​)n(Fe2​O3​)n(Fe)m(Fe)÷ M(Fe2​O3​)× 2/1× M(Fe)

For the reaction Fe2O3 + 3CO → 2Fe + 3CO2, what mass m of Fe forms from 32 g of Fe2O3? Assume the other reactants are in excess.

M(Fe2O3) = 159.69 g/molM(Fe) = 55.85 g/mol
m = g
2.Easy
m(CaCO3​)n(CaCO3​)n(CO2​)m(CO2​)÷ M(CaCO3​)× 1/1× M(CO2​)

For the reaction CaCO3 → CaO + CO2, what mass m of CO2 forms from 5 g of CaCO3? Assume the other reactants are in excess.

M(CaCO3) = 100.09 g/molM(CO2) = 44.01 g/mol
m = g
3.Medium
m(X)n(X)n(H2​O)m(H2​O)÷ M(X)× 2/ν× M(H2​O)

10 g of H2 and 64 g of O2 react according to 2H2 + O2 → 2H2O. What mass m of H2O can form?

M(H2) = 2.016M(O2) = 32M(H2O) = 18.02 g/mol
m = g
4.Medium
m(X)n(X)n(CO2​)m(CO2​)÷ M(X)× 1/ν× M(CO2​)

6 g of CH4 and 24 g of O2 react according to CH4 + 2O2 → CO2 + 2H2O. What mass m of CO2 can form?

M(CH4) = 16.04M(O2) = 32M(CO2) = 44.01 g/mol
m = g
5.Hard
m(H2​)n(H2​)n(H2​O)m(H2​O)÷ M(H2​)× 2/2× M(H2​O)

In the reaction 2H2 + O2 → 2H2O, 20 g of H2 reacts completely (the other reactants are in excess) and 162.7 g of H2O is collected. Find the percent yield Y.

M(H2) = 2.016 g/molM(H2O) = 18.02 g/molactual: 162.7 g
Y = %
6.Hard
m(CaCO3​)n(CaCO3​)n(CO2​)m(CO2​)÷ M(CaCO3​)× 1/1× M(CO2​)

In the reaction CaCO3 → CaO + CO2, 16 g of CaCO3 reacts completely (the other reactants are in excess) and 5.28 g of CO2 is collected. Find the percent yield Y.

M(CaCO3) = 100.09 g/molM(CO2) = 44.01 g/molactual: 5.28 g
Y = %

Answer key

  1. 1. m = 22.38 g
  2. 2. m = 2.199 g
  3. 3. m = 72.08 g
  4. 4. m = 16.46 g
  5. 5. Y = 91 %
  6. 6. Y = 75.05 %

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