2.3.2 Redox reactions

• What is oxidation defined as in redox reactions?

  Loss of electrons
• An oxidizing agent gains electrons and causes another substance to be oxidized.


  True
• A reducing agent donates electrons
• Steps of the half-equation method for balancing redox equations

  1️⃣ Write separate half-equations

  2️⃣ Balance atoms (except H and O)

  3️⃣ Balance oxygen with H2O

  4️⃣ Balance hydrogen with H+

  5️⃣ Balance charges with e-

  6️⃣ Equalize electron transfer

  7️⃣ Combine and simplify
• Hydrogen is balanced in the half-equation method by adding H+
• What is the charge balancing step for the oxidation half-equation Fe2+ → Fe3+?

  Fe2+ → Fe3+ + e-
• The balanced redox equation for the reaction between Fe2+ and Cr2O72- is 6Fe2+ + Cr2O72- + 14H+ → 6Fe3+ + 2Cr3+ + 7H2O.


  True
• The process where a substance gains electrons is called reduction
• What is the definition of oxidation in redox reactions?

  The loss of electrons
• Oxidation involves the loss of electrons by a substance.


  True
• What is an oxidizing agent in redox reactions?

  A substance that gains electrons
• Match the agent with its definition:

  Oxidizing Agent ↔️ Accepts electrons, oxidizes other substances

  Reducing Agent ↔️ Donates electrons, reduces other substances
• In the reaction Fe2+ + 2Ag+ → Fe3+ + 2Ag, Fe2+ acts as the reducing agent.
• Balancing redox equations ensures that both mass and charge are conserved.

  True
• Decomposition is a redox reaction where a single reactant breaks down into two or more simpler products.
• What type of redox reaction is used in batteries to generate electricity?

  Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)
• Reduction involves the gain of electrons by a substance.

  True
• Reduction is the gain of electrons
• What does an oxidizing agent do during a redox reaction?

  Accepts electrons
• In the reaction Fe2+ + 2Ag+ → Fe3+ + 2Ag, Ag+ is the oxidizing agent.


  True
• How is oxygen balanced in the half-equation method?

  Adding H2O
• Balancing redox equations ensures both mass and charge are conserved.


  True
• In the reduction half-equation Cr2O72- + 14H+ + 6e- → 2Cr3+ + 7H2O, the substance accepting electrons is Cr2O72-
• What is the process where a substance loses electrons called?

  Oxidation
• Match the terms with their definitions:

  Oxidizing Agent ↔️ Accepts electrons, oxidizes other substances

  Reducing Agent ↔️ Donates electrons, reduces other substances
• Reduction is the process where a substance gains electrons.
• Reduction is the process where a substance loses electrons.

  False
• A reducing agent is a substance that loses electrons.
• In the reaction Fe2+ + 2Ag+ → Fe3+ + 2Ag, which substance is the oxidizing agent?

  Ag+
• Steps for balancing redox equations using the half-equation method:

  1️⃣ Write separate half-equations

  2️⃣ Balance atoms except hydrogen and oxygen

  3️⃣ Balance oxygen by adding H2O

  4️⃣ Balance hydrogen by adding H+

  5️⃣ Balance charges by adding e-

  6️⃣ Equalize electron transfer

  7️⃣ Combine and simplify
• What is the definition of a combination redox reaction?

  Two or more reactants combine
• Match the redox reaction type with its example:

  Combination ↔️ 2Mg(s) + O2(g) → 2MgO(s)

  Decomposition ↔️ 2H2O(l) → 2H2(g) + O2(g)

  Displacement ↔️ Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

  Combustion ↔️ CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
• Corrosion prevention methods like galvanizing use redox reactions to protect metals from rust.
• Oxidation is defined as the loss of electrons
• What is an oxidizing agent in a redox reaction?

  A substance that accepts electrons
• A reducing agent loses electrons, causing another substance to be reduced.

  True
• Steps involved in balancing redox equations using the half-equation method

  1️⃣ Write separate half-equations

  2️⃣ Balance atoms except hydrogen and oxygen

  3️⃣ Add water (H2O) to the oxygen-deficient side

  4️⃣ Add hydrogen ions (H+) to the hydrogen-deficient side

  5️⃣ Balance charges by adding electrons (e-)

  6️⃣ Equalize electron transfer by multiplying half-equations
• Electrons are added to the side with the higher positive charge to balance charges in a half-equation.

  True
• What is the balanced redox equation for Cr2O72- + Fe2+ → Cr3+ + Fe3+ using the half-equation method?

  6Fe2+ + Cr2O72- + 14H+ → 6Fe3+ + 2Cr3+ + 7H2O
• In a combination redox reaction, two or more reactants combine to form a single product