Chemical Rections Problem Set

This problem set was developed by S.E. Van Bramer for Chemistry 145 at Widener University.



  1. For the following reactions: Name the reactants and products, Balance the equation, Calculate the molecular weight of the reactants and products, Classify the reaction type.
    1. Fe2O3 (s ) + CO (g) -> FeO (s) + CO2 (g)
      1. Iron (III) oxide + carbon monoxide -> Iron (II) oxide + carbon dioxide
      2. Fe2O3 (s ) + CO (g) -> 2 FeO (s) + CO2 (g)
      3. Molecular Weight
        1. Fe2O3 159.6922 g mole-1
        2. CO 28.010 g mole-1
        3. FeO 71.846 g mole-1
        4. CO2 44.010 g mole-1
      4. Redox reaction. (Iron (III) oxide is reduced)

    2. FeO (s) + CO (g) -> Fe (s) + CO2 (g)
      1. Iron (II) oxide + carbon monoxide -> iron metal and carbon dioxide
      2. FeO (s) + CO (g) -> Fe (s) + CO2 (g)
      3. Molecular Weight
        1. FeO 71.546 g mole-1
        2. CO 28.010 g mole-1
        3. Fe 55.847 g mole-1
        4. CO2 44.101 g mole-1
      4. Redox reaction (Iron (II) oxide is reduced)

    3. C12H22O11 (s) + O2 (g) -> CO2 (g) + H2O (g)
      1. ? (I was thinking of sucrose but there are other compounds with this formula) + oxygen -> carbon dioxide + water
      2. C12H22O11 (s) + 12 O2 (g) -> 12 CO2 (g) + 11 H2O (g)
      3. Molecular Weight
        1. C12H22O11 342.299 g mole-1
        2. O2 31.999 g mole-1
        3. CO2 44.101 g mole-1
        4. H2O 18.015 g mole-1
      4. Combustion and redox reaction. (Sucrose is oxidized.)

    4. Fe (s) + O2 (g) -> Fe2O3 (s)
      1. Iron metal + oxygen -> Iron (III) oxide
      2. 4 Fe (s) + 3 O2 (g) -> 2 Fe2O3 (s)
      3. Molecular Weight
        1. Fe 55.847 g mole-1
        2. O2 31.999 g mole-1
        3. Fe2O3 159.6922 g mole-1
      4. Redox reaction (iron is oxidezed)

    5. Ca (s) + H2O (l) -> Ca(OH)2 (aq) + H2 (g)
      1. Calcium + water -> calcium hydroxide and hydrogen
      2. Ca (s) + 2 H2O (l) -> Ca(OH)2 (aq) + H2 (g)
      3. Molecular Weight
        1. Ca 40.08 g mole-1
        2. H2O 18.015 g mole-1
        3. Ca(OH)2 74.09 g mole-1
        4. H2 2.016 g mole-1


  2. Write a balanced equation for the following reactions. Determine if any of the reactants or products are soluble in water. Classify the type of reaction. Identify any gas that is produced. Identify any precipitate that is produced. Are the reactants soluble in water? Is it a redox reaction? What is the oxidation number for each element in the reactants and the products?
    1. Aluminum metal is oxidized by oxygen (from the air) to form aluminum oxide.
      1. 4 Al (s) + 3 O2 (g) -> 2 Al2O3 (s)
      2. Oxidation Numbers
        3. (
        Al 0 (element in it's natural state)
        O2 O0 (element in it's natural state)
        Al2O3 Al, 3+; O 2-only common oxidation state for these two elements)

    2. Sodium oxide reacts with carbon dioxide to form sodium carbonate.
      1. Na2O + CO2 (g) -> Na2CO3
      2. Oxidation Numbers
        3. Na2O Na, 1+; O, 2- (common oxidation states for these elements)
        CO2 C, 4+ O, 2- (start with Oxygen at 2-, then determine carbon)
        Na2CO3 Na, 1+ C 4+ O 2- (know carbonate is 2-, and Oxygen is 2-)

    3. Calcium metal reacts with water to form calcium hydroxide and hydrogen gas
      1. Ca + 2 H2O -> Ca(OH)2 + H2 (g)
      2. Oxidation Numbers
        3. Ca 0 (element in it's natural state)
        H2O H, 1+ O, 2- (start with O at 2-)
        Ca(OH)2 Ca, 2+; O, 2-; H 1+
        H2 0 (element in it's natural state)

    4. Potassium nitrate decomposes to form potassium nitrite and oxygen.
      1. 2 KNO3 -> 2 KNO2 + O2
      2. Oxidation Numbers
        3. KNO3 K, 1+; N, 5+; O, 2- (know nitrate is 1- and O is 2-)
        KNO2 K, 1+; N, 3+; O, 2- (know nitrite is 1-, and O is 2-)
        O2 0 (element in natural state)

    5. Barium metal reacts with Iron (III) sulfate to produce barium sulfate and iron metal.
      1. 3 Ba (s) + Fe2(SO4)3 (aq) -> 3 BaSO4 (s) + 2 Fe (s)
      2. Oxidation Numbers
        3. Ba 0 (element in it's natural state)
        Fe2(SO4)3 Fe3+ S6+ O2- (know sulfate is 2-, so determine Fe. Since O 2-, determine S)
        BaSO4 Ba2+ S6+ O2-
        Fe 0 (element in it's natural state)

    6. Barium chloride reacts with sodium sulfate to produce barium sulfate and sodium chloride.
      1. BaCl2 + Na2SO4 -> BaSO4 + 2 NaCl
      2. Oxidation Number
        3. BaCl2 Ba2+, Cl1-
        Na2SO4 Na1+ S6+ O2-
        BaSO4 Ba2+ S6+ O2-
        NaCl Na1+ Cl1-

    7. Bismuth (III) oxide and zinc metal react to produce zinc (II) oxide and bismuth metal.
      1. Bi2O3 + 3 Zn (s) -> 3 ZnO + 2 Bi(s)
      2. Oxidation Number
        3. Bi2O3 Bi3+ O2-
        Zn 0
        ZnO Zn2+ O2-
        Bi 0

    8. Calcium metal reacts with phosphorus to produce calcium phosphide.
      1. 3 Ca + 2 P -> Ca3P2
      2. Oxidation Number
        3. Ca 0
        P 0
        Ca3P2 Ca2+ P3- (from position on periodic table)

    9. Copper metal reacts with sulfuric acid and water to produce copper sulfate pentahydrate and sulfur dioxide.
      1. Cu (s) + 2 H2SO4 + 3 H2O -> CuSO4*5 H2O + SO2
      2. Oxidation Number
        3. Cu Cu0 (element in it's natural state)
        H2SO4 H0 S6+ O2-
        H2O H1+ O2-
        CuSO4*5 H2O Cu2+ S6+ O2- H1+ O2-
        SO2 S4+ O2-

    10. The combustion of decane.
      1. 2 C10H22 + 31 O2 -> 20 CO2 + 22 H2O
      2. Oxidation Number
        3. C10H22 2 C3- 8 C2- H1+ (This is not at all obvious without the chemical structure)
        O2 O0 (element in it's natural state)
        CO2 C4+ O2-
        H2O H1+ O2-

    11. The combustion of pamoic acid (C23H16O4).
      1. C23H16O4 + 25 O2 -> 23 CO2 + 8 H2O
      2. Oxidation Numbers
        3. C23H16O4 (dependent upon structure of molecule, the concept of "oxidation numbers" is not readily applied to a molecule this complex.)
        O2 O0
        CO2 C4+ O2-
        H2O H1+ O2-

    12. A solution of hydrochloric acid reacts with a solid calcium bicarbonate to produce water, carbon dioxide, and calcium chloride.
      1. 2 HCl (aq) + Ca(HCO3)2 (s) -> 2 H2O (l) + 2 CO2 (g) + CaCl2 (aq)
      2. Oxidation Numbers
        3. HCl H1+ Cl1-
        Ca(HCO3)2 Ca2+ H1+ C4+ O2-
        H2O H1+ O2-
        CO2 C4+ O2-
        CaCl2 Ca2+ Cl1-

    13. A solution of acetic acid reacts with solid iron (II) hydroxide.
      1. CH3COOH (aq) + Fe(OH)2 (s)-> H2O (l) + Fe(CH3COO)2 (aq)
      2. Oxidation Numbers
        3. CH3COOH C3- C3+ O2- H1+
        Fe(OH)2 Fe2+ O2- H1+
        H2O O2- H1+
        Fe(CH3COO)2 Fe2+ C3- C3+ O2- H1+

    14. hydrofluoric acid reacts with sodium hydroxide.
      1. HF + NaOH -> H2O + NaF
      2. Oxidation Numbers
        HF H1+ F1-
        NaOH Na1+ O2- H1+

  • Determine if a precipitate forms when the following solutions are mixed. Write the overall equation, the total ionic equation, and the net ionic equation.
    1. A solution of sodium fluoride is mixed with a solution of barium nitrate.
      1. 2 NaF (aq) + Ba(NO3)2 (aq) -> BaF2 (s) + 2 NaNO3 (aq)
      2. 2 Na1+ (aq) + 2 F1- (aq) + Ba2+ (aq) +2 NO31- (aq) -> BaF2 (s) + 2 Na1+ (aq) + 2 NO31- (aq)
      3. 2 F1- (aq) + Ba2+ (aq) -> BaF2 (s)

    2. A solution of ammonium carbonate is mixed with a solution of calcium acetate.
      1. (NH4)2CO3 (aq) + Ca(CH3COO)2 (aq) -> CaCO3 (s) + 2 NH4CH3COO (aq)
      2. 2 NH41+ (aq) + CO32- (aq) + Ca2+ (aq) + 2 CH3COO1- (aq) -> CaCO3 (s) + 2 NH41+(aq) + 2 CH3COO1- (aq)
      3. CO32- (aq) + Ca2+ (aq) -> CaCO3 (s)

    3. A solution of potassium bromide is mixed with a solution of ammonium sulfate.
      1. 2 KBr (aq) + (NH4)2SO4 (aq) -> K2SO4 (aq) + 2 NH4Br (aq)
      2. K1+ (aq) + Br1- (aq) + 2 NH41+ (aq) + SO42- (aq) -> K1+ (aq) + Br1- (aq) + 2 NH41+ (aq) + SO42- (aq)
      3. No net reaction, all products are soluble.

    4. A solution of sodium chromate is mixed with a solution of barium sulfate.
      1. Na2Cr2O4 (aq) + BaSO4 (s) -> BaCr2O4 (s) + Na2SO4 (aq)
      2. Na1+ (aq) + Cr2O4 (aq) + BaSO4 (s) -> BaCr2O4 (s) + 2 Na1+ (aq) + SO42- (aq)
      3. No net ionic reaction because one of the reactants is insoluble. Since it can not go into solution, no Ba2+ (aq) ions are produced. So no reaction can occur. This may not be clear in the overall equation, but the total ionic equation shows this clearly.


  • Fill in the following table of solubility (yes means compound is soluble).

    • F1- Cl1- Br1- I1- nitrate sulfate chlorate acetate carbonate sulfide hydroxide
    Li1+ yes yes yes yes yes yes yes yes yes yes yes
    Na1+ yes yes yes yes yes yes yes yes yes yes yes
    K1+ yes yes yes yes yes yes yes yes yes yes yes
    Mg2+ no yes yes yes yes yes yes yes no no no
    Ca2+ no yes yes yes yes yes yes yes no no no
    Ba2+ no yes yes yes yes no yes yes no no no
    Sr2+ no yes yes yes yes no yes yes no no no
    Ag1+ yes no no no yes yes yes yes no no no
    Pb2+ no no no no yes no yes yes no no no
    Hg22+ yes no no no yes yes yes yes no no no
    NH41+ yes yes yes yes yes yes yes yes yes yes yes




    This page is maintained by
    Scott Van Bramer
    Department of Chemistry
    Widener University
    Chester, PA 19013

    Please send any comments, corrections, or suggestions to svanbram@science.widener.edu.

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    Last Updated 1/5/96