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(CO2​)m(CO2​)÷ M(CH4​)× 1/1× M(CO2​)

For the reaction CH4 + 2O2 → CO2 + 2H2O, what mass m of CO2 forms from 5 g of CH4? Assume the other reactants are in excess.

M(CH4) = 16.04 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 25 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(AlCl3​)m(AlCl3​)÷ M(X)× 2/ν× M(AlCl3​)

4 g of Al and 80 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(NH3​)m(NH3​)÷ M(X)× 2/ν× M(NH3​)

16 g of N2 and 16 g of H2 react according to N2 + 3H2 → 2NH3. What mass m of NH3 can form?

M(N2) = 28.02M(H2) = 2.016M(NH3) = 17.03 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 41.68 g of H2O is collected. Find the percent yield Y.

M(C3H8) = 44.1 g/molM(H2O) = 18.02 g/molactual: 41.68 g
Y = %
6.Hard
m(Fe2​O3​)n(Fe2​O3​)n(CO2​)m(CO2​)÷ M(Fe2​O3​)× 3/1× M(CO2​)

In the reaction Fe2O3 + 3CO → 2Fe + 3CO2, 24 g of Fe2O3 reacts completely (the other reactants are in excess) and 15.48 g of CO2 is collected. Find the percent yield Y.

M(Fe2O3) = 159.69 g/molM(CO2) = 44.01 g/molactual: 15.48 g
Y = %

Answer key

  1. 1. m = 13.72 g
  2. 2. m = 63.55 g
  3. 3. m = 19.77 g
  4. 4. m = 19.45 g
  5. 5. Y = 85 %
  6. 6. Y = 78.01 %

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