The World of Astoria Bob

CH 221Z Clatsop Community College Fall 2025

In-Class Worksheet 7, Week 9

Dr. A. Coomar

Balancing Chemical Equations

  1. Balance the following unbalanced reactions.
    1. 2H2 + O2 → 2H2O
    2. 2C2H6 + 7O2 → 6H2O + 4CO2
    3. N2 + 3H2 → 2NH3
    4. 2N2 + 5O2 → 2N2O5
    5. Write a balanced equation for the decomposition of ammonium nitrate to form molecular nitrogen, molecular oxygen, and water.
      (Hint: Balance oxygen last, since it is present in more than one molecule on the right side of the equation.)
      2NH4NO3 → 2N2 + O2 + 4H2O
    6. When carbon dioxide is dissolved in an aqueous solution of sodium hydroxide, the mixture reacts to yield aqueous sodium carbonate and liquid water.
      Write balanced molecular, complete ionic, and net ionic equations for this process.
      CO2 + 2NaOH(aq) → Na2CO3(aq) + H2O(l)
    7. Write balanced molecular, complete ionic, and net ionic equations for the process:
      NaCl(aq) + H2O(l) → NaOH(aq) + H2(g) + Cl2(g)

Classifying Chemical Reactions

  1. Predict the result of mixing reasonably concentrated solutions of the following ionic compounds. If precipitation is expected, write a balanced net ionic equation for the reaction.
    1. potassium sulfate and barium nitrate
    2. lithium chloride and silver acetate
    3. lead nitrate and ammonium carbonate
    See my AI query for answers to this question.
  2. Write balanced chemical equations for the acid-base reactions described here:
    1. the weak acid hydrogen hypochlorite reacts with water
      HOCl + H2O → H3O+ + OCl-
    2. a solution of barium hydroxide is neutralized with a solution of nitric acid
      Ba(OH)2(aq) + 2HNO3(aq) → Ba(NO3)2(aq) + 2H2O
  3. Write the net ionic equation representing the neutralization of any strong acid with an ionic hydroxide.
    (Hint: Consider the ions produced when a strong acid is dissolved in water.)
  4. Assign oxidation states to the elements whose atoms are underlined in each of the following compounds or ions:
    1. KNO3
      N is 5+
    2. AlH3
      Al is 3+
    3. NH4+
      N is 5+
    4. H2PO4-
      P is 5+