Interactive Practice on Stoichiometry

Choose the correct answer.

1. The coefficients in a chemical equation represent the
   • masses of reactants and products
   • relative numbers of moles of reactants and products
   • number of L each compound occupies
2. Nitrogen gas combines with hydrogen gas to make ammonia. What is the mole ratio of nitrogen to ammonia?
   • 1:1
   • 1:2
   • 1:3
3. Iron combines with oxygen gas to make iron (III) oxide. What are the coefficients once this equation is balanced?
   • 1,1,3
   • 4,3,2
   • 2,3,1
4. In the equation you found in #3, how many moles of oxygen are needed to react with 0.345 moles of iron??
   • 0.115 moles
   • 0.259 moles
   • 0.460 moles
5. For the reaction 2Na + Cl₂ --> 2NaCl, if 500 g each of sodium and chlorine are supplied, which is the limiting reactant?
   • sodium
   • chlorine
   • stoichiometric ratio
6. Consider the reaction of copper sulfate with zinc metal. CuSO₄ + Zn --> Cu + ZnSO₄. 2.9 g Zinc will produce what mass copper?
   • 2.8 g
   • 3.7 g
   • 5.7 g
   • 8.6 g
7. In a chemical reaction, the reactant that is NOT the limiting reactant is called the
   • catalyst
   • product
   • excess reactant
   • none of these
8. Nitrogen combines with hydrogen to form ammonia. How many moles of nitrogen are required to produce 9 moles ammonia? (nitrogen and hydrogen are diatomic).
   • 4.5
   • 9
   • 13.5
   • 18
9. To balance a chemical equation, you should only adjust the
   • coefficients
   • subscripts
10. True or false: The total mass of the reactants must equal the total mass of the products.
    • true
    • false

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