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(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 32 g of CaCO3? Assume the other reactants are in excess.

M(CaCO3) = 100.09 g/molM(CO2) = 44.01 g/mol
m = g
2.Easy
m(Na)n(Na)n(NaCl)m(NaCl)÷ M(Na)× 2/2× M(NaCl)

For the reaction 2Na + Cl2 → 2NaCl, what mass m of NaCl forms from 50 g of Na? Assume the other reactants are in excess.

M(Na) = 22.99 g/molM(NaCl) = 58.44 g/mol
m = g
3.Medium
m(X)n(X)n(NaCl)m(NaCl)÷ M(X)× 2/ν× M(NaCl)

10 g of Na and 80 g of Cl2 react according to 2Na + Cl2 → 2NaCl. What mass m of NaCl can form?

M(Na) = 22.99M(Cl2) = 70.9M(NaCl) = 58.44 g/mol
m = g
4.Medium
m(X)n(X)n(Fe)m(Fe)÷ M(X)× 2/ν× M(Fe)

4 g of Fe2O3 and 40 g of CO react according to Fe2O3 + 3CO → 2Fe + 3CO2. What mass m of Fe can form?

M(Fe2O3) = 159.69M(CO) = 28.01M(Fe) = 55.85 g/mol
m = g
5.Hard
m(C3​H8​)n(C3​H8​)n(H2​O)m(H2​O)÷ M(C3​H8​)× 4/1× M(H2​O)

In the reaction C3H8 + 5O2 → 3CO2 + 4H2O, 30 g of C3H8 reacts completely (the other reactants are in excess) and 36.78 g of H2O is collected. Find the percent yield Y.

M(C3H8) = 44.1 g/molM(H2O) = 18.02 g/molactual: 36.78 g
Y = %
6.Hard
m(Al)n(Al)n(AlCl3​)m(AlCl3​)÷ M(Al)× 2/2× M(AlCl3​)

In the reaction 2Al + 3Cl2 → 2AlCl3, 12 g of Al reacts completely (the other reactants are in excess) and 53.96 g of AlCl3 is collected. Find the percent yield Y.

M(Al) = 26.98 g/molM(AlCl3) = 133.33 g/molactual: 53.96 g
Y = %

Answer key

  1. 1. m = 14.07 g
  2. 2. m = 127.1 g
  3. 3. m = 25.42 g
  4. 4. m = 2.798 g
  5. 5. Y = 75.01 %
  6. 6. Y = 90.99 %

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