Question

1. Identify whether the following compounds are an acid, base or salt.
   1. H₂SO₄
   2. CaNO₃
   3. NaOH
   4. NH₃
   5. CHOOH

2. What is the pH of a solution with [H₃O⁺] = 1.21 x 10^-9 M

3. A solution has a pH = 3.89. What is the concentration of hydronium ion and hydroxide ion in that solution?

4. Write the conjugate acid or conjugate base for the following species.
   1. OH^-
   2. HCl
   3. NH₄⁺
   4. NO₃^-
   5. H₃O⁺

5. Identify whether the following reaction is an oxidation or a reduction.
   1. Ni²⁺ + 2e^- → Ni
   2. 2Br^- → Br₂ + 2e^-
   3. O₂ + 4e^- → 2O^2-
   4. Zn → 2e^- + Zn²⁺
   5. H₂ → 2H⁺ + 2e^-

6. In the following reactions, identify which reactants are the oxidizing agent and which are the reducing agents.
   1. 2S₂O₃^2- (aq) + I₂ (s) → 2I^- (aq) + S₄O₆^2- (aq)
   2. NO₃^- (aq) + Zn (s) → Zn²⁺ (aq) + NO₂(g)

7. Assign oxidation numbers to all the atoms in the following redox reactions.
   1. I₂O₅ (s) + 5CO (g) → I₂ (g) + 5CO₂(g)
   2. 2Cr₂O₃ (s) + 3C (s) → 4Cr (s) + 3CO₂(g)

8. Balance the following half reactions in basic solution. (5 Marks)
   1. ClO₃^- (aq) → ClO₄^- (aq)
   2. Zn (s) → Zn²⁺ (aq)
   3. BrO₃^- (aq) → Br^- (aq)
   4. IO₃^- (aq) → I₂ (s)
   5. Sn²⁺ → Sn⁴⁺

Answer 1