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(CH4​)n(CH4​)n(H2​O)m(H2​O)÷ M(CH4​)× 2/1× M(H2​O)

For the reaction CH4 + 2O2 → CO2 + 2H2O, what mass m of H2O forms from 16 g of CH4? Assume the other reactants are in excess.

M(CH4) = 16.04 g/molM(H2O) = 18.02 g/mol
m = g
2.Easy
m(Al)n(Al)n(AlCl3​)m(AlCl3​)÷ M(Al)× 2/2× M(AlCl3​)

For the reaction 2Al + 3Cl2 → 2AlCl3, what mass m of AlCl3 forms from 100 g of Al? Assume the other reactants are in excess.

M(Al) = 26.98 g/molM(AlCl3) = 133.33 g/mol
m = g
3.Medium
m(X)n(X)n(AlCl3​)m(AlCl3​)÷ M(X)× 2/ν× M(AlCl3​)

8 g of Al and 24 g of Cl2 react according to 2Al + 3Cl2 → 2AlCl3. What mass m of AlCl3 can form?

M(Al) = 26.98M(Cl2) = 70.9M(AlCl3) = 133.33 g/mol
m = g
4.Medium
m(X)n(X)n(NaCl)m(NaCl)÷ M(X)× 2/ν× M(NaCl)

24 g of Na and 64 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
5.Hard
m(Fe2​O3​)n(Fe2​O3​)n(Fe)m(Fe)÷ M(Fe2​O3​)× 2/1× M(Fe)

In the reaction Fe2O3 + 3CO → 2Fe + 3CO2, 10 g of Fe2O3 reacts completely (the other reactants are in excess) and 5.25 g of Fe is collected. Find the percent yield Y.

M(Fe2O3) = 159.69 g/molM(Fe) = 55.85 g/molactual: 5.25 g
Y = %
6.Hard
m(N2​)n(N2​)n(NH3​)m(NH3​)÷ M(N2​)× 2/1× M(NH3​)

In the reaction N2 + 3H2 → 2NH3, 12 g of N2 reacts completely (the other reactants are in excess) and 10.21 g of NH3 is collected. Find the percent yield Y.

M(N2) = 28.02 g/molM(NH3) = 17.03 g/molactual: 10.21 g
Y = %

Answer key

  1. 1. m = 35.95 g
  2. 2. m = 494.2 g
  3. 3. m = 30.09 g
  4. 4. m = 61.01 g
  5. 5. Y = 75.06 %
  6. 6. Y = 70 %

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