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

For the reaction 2H₂ + O₂ → 2H₂O, what mass m of H₂O forms from 100 g of H₂? Assume the other reactants are in excess.

M(H₂) = 2.016 g/molM(H₂O) = 18.02 g/mol

m = g

2.Easy

For the reaction CaCO₃ → CaO + CO₂, what mass m of CaO forms from 32 g of CaCO₃? Assume the other reactants are in excess.

M(CaCO₃) = 100.09 g/molM(CaO) = 56.08 g/mol

m = g

3.Medium

8 g of Fe₂O₃ and 80 g of CO react according to Fe₂O₃ + 3CO → 2Fe + 3CO₂. What mass m of CO₂ can form?

M(Fe₂O₃) = 159.69M(CO) = 28.01M(CO₂) = 44.01 g/mol

m = g

4.Medium

16 g of Na and 40 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

In the reaction CH₄ + 2O₂ → CO₂ + 2H₂O, 20 g of CH₄ reacts completely (the other reactants are in excess) and 38.41 g of CO₂ is collected. Find the percent yield Y.

M(CH₄) = 16.04 g/molM(CO₂) = 44.01 g/molactual: 38.41 g

Y = %

6.Hard

In the reaction CH₄ + 2O₂ → CO₂ + 2H₂O, 6 g of CH₄ reacts completely (the other reactants are in excess) and 10.11 g of H₂O is collected. Find the percent yield Y.

M(CH₄) = 16.04 g/molM(H₂O) = 18.02 g/molactual: 10.11 g

Y = %

Answer key

1. m = 893.8 g
2. m = 17.93 g
3. m = 6.614 g
4. m = 40.67 g
5. Y = 70 %
6. Y = 74.99 %

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