Practice using OIL RIG to decide what is oxidized and reduced in redox reactions, and identify oxidizing and reducing agents.
Read each problem carefully. Use OIL RIG: Oxidation Is Loss of electrons, Reduction Is Gain of electrons. Show your work in the space provided.
Identify electron loss, electron gain, oxidizing agents, and reducing agents
Chemistry - Grade 9-12
- 1
In your own words, explain what OIL RIG means in chemistry.
- 2
Magnesium reacts with oxygen to form magnesium oxide: 2Mg + O2 -> 2MgO. In this reaction, magnesium atoms become Mg2+ ions. Is magnesium oxidized or reduced? Explain.
- 3
Chlorine reacts with sodium to form sodium chloride: 2Na + Cl2 -> 2NaCl. Each chlorine atom becomes Cl- in the product. Is chlorine oxidized or reduced? Explain.
- 4
In the reaction Zn + Cu2+ -> Zn2+ + Cu, identify the substance that is oxidized and the substance that is reduced.
- 5
For the half-reaction Fe2+ -> Fe3+ + e-, state whether iron is oxidized or reduced, and explain how you know.
- 6
For the half-reaction Ag+ + e- -> Ag, state whether silver is oxidized or reduced, and explain how you know.
- 7
In the reaction 2Al + 3Cu2+ -> 2Al3+ + 3Cu, which reactant is the reducing agent? Explain.
- 8
In the reaction 2Al + 3Cu2+ -> 2Al3+ + 3Cu, which reactant is the oxidizing agent? Explain.
- 9
Assign oxidation numbers to sulfur in H2S and in S. Then decide whether sulfur is oxidized or reduced in the change H2S -> S.
- 10
Assign oxidation numbers to manganese in MnO4- and Mn2+. Then decide whether manganese is oxidized or reduced in the change MnO4- -> Mn2+.
- 11
A student says, "Oxidation always means a substance gains oxygen." Explain why this statement is incomplete or misleading.
- 12
Consider the reaction 2K + Br2 -> 2KBr. Potassium becomes K+ and bromine becomes Br-. Identify what is oxidized, what is reduced, the reducing agent, and the oxidizing agent.