Redox Answers

Practice for Redox Reactions

Write the formula and then assign oxidation numbers for the following ions:

1. 5
2. 6
3. 6
4. -1
5. -2
6. 5
7. 3
8. 7
9. 5
10. 1
11. 3

For the following reaction:

2 Fe₂O₃(s) + 3C (s) ——> 4Fe(s) + 3CO₂(g)

1. Carbon is oxidized.
2. Iron (III) is reduced.
3. Carbon is the reducing agent.
4. Iron (III) is the oxidizing agent.

For the following reaction:

C₇H₁₆ + 11 O₂ ——> 7 CO₂ + 8 H₂O

1. Balance the reaction.
2. Heptane (C₇H₁₆ ) is oxidized.
3. Oxygen is reduced.
4. Heptane (C₇H₁₆ )is the reducing agent.
5. Oxygen is the oxidizing agent.

Balance the following reactions

Cu⁺² + Ni(s) —> Cu(s) + Ni⁺²
Sn⁺⁴ + 2Fe(s) —> Sn(s) + 2 Fe⁺²
Co(s) + Pb+2 —> Co⁺² + Pb(s)
2Li(s) reacts with Zn⁺² —> Zn(s) + 2Li⁺

Challenge! Why don't these reactions occur?

(Look at the metal reactivity series, the metal compound must be more reactive than the ionic compound for electrons to move from the metal to the ion.)
Ni⁺² + Cu(s) —> no reaction
Iron⁺² + Sn(s) —>no reaction

What is the most important redox reaction in your life?

Explain why it is important to you?
You do not need to balance it, yet….