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.