17 4.1 Chemical Equations

Practice questions

1. 1. 1. From the statement ‘nitrogen and hydrogen react to produce ammonia,’ identify the reactants and products.
         1. Reactants: ammonia and nitrogen. Products: hydrogen.
         2. Reactants: nitrogen. Products: ammonia and hydrogen.
         3. Reactants: ammonia. Products: nitrogen and hydrogen.
         4. Reactants: nitrogen and hydrogen. Products: ammonia.
      2. From the statement ‘sodium metal reacts with water to produce sodium hydroxide and hydrogen,’ identify the reactants and the products.
         1. Reactants: sodium and water. Products: sodium hydroxide and hydrogen.
         2. Reactants: sodium, hydrogen and water. Products: sodium hydroxide.
         3. Reactants: sodium hydroxide and hydrogen. Products: sodium and water.
         4. Reactants: sodium hydroxide. Products: sodium, hydrogen and water.
      3. What does the arrow in a chemical equation represent?
         1. The conversion of reactants into products.
         2. The reactants and products are unrelated.
         3. The addition of reactants.
         4. An equal sign.
      4. In a balanced chemical equation, which of the following is conserved?
         1. Mass and volume.
         2. Mass only.
         3. Volume only.
         4. Mass and moles.
      5. Which of the following statements is true about a chemical equation?
         1. The physical state of the reactants and products is written as a superscript after each substance.
         2. The coefficients represent the ratio of amounts of reactants and products.
         3. The reactants and products are always in the same physical state.
         4. The conditions required for the reaction to occur can be written before the reactants.
      6. When balancing a chemical equation, which of the following is adjusted to ensure the conservation of mass?
         1. Subscripts.
         2. Nothing needs to be adjusted.
         3. The state of matter.
         4. Coefficients.
      7. What does a chemical equation represent?
         1. A summary of the periodic table.
         2. A list of chemical elements.
         3. A recipe for a chemical reaction.
         4. A list of chemical compounds.
      8. Which of the following is a reactant in the chemical equation for photosynthesis: [latex]\ce{6CO_{2}} + \ce{6H_{2}O} {\rightarrow} \ce{C_{6}H_{12}O_{6}} + \ce{6O_{2}}[/latex].
         1. [latex]\ce{CO_{2}}[/latex]
         2. [latex]\ce{O_{2}}[/latex]
         3. [latex]\ce{C_{6}H_{12}O_{6}}[/latex]
         4. [latex]\ce{H_{2}}[/latex]
      9. From the statement ‘magnesium hydroxide reacts with nitric acid to produce magnesium nitrate and water,’ identify the reactants and the products.
         1. Reactants: magnesium nitrate and water. Products: magnesium hydroxide and nitric acid.
         2. Reactants: magnesium hydroxide. Products: magnesium nitrate and water.
         3. Reactants: magnesium hydroxide and water. Products: magnesium nitrate and nitric acid.
         4. Reactants: magnesium hydroxide and nitric acid. Products: magnesium nitrate and water.
      10. From the statement ‘propane reacts with oxygen to produce carbon dioxide and water,’ identify the reactants.
          1. Oxygen only.
          2. Carbon dioxide and water.
          3. Propane only.
          4. Propane and oxygen.

Answers

1. 1. d
   2. a
   3. a
   4. b
   5. b
   6. d
   7. c
   8. a
   9. d
   10. d