Redox reactions

• What does oxidation mean in chemistry?


  Oxidation refers to the loss of electrons.
• What does reduction mean in chemistry?


  Reduction refers to the gain of electrons.
• What is the mnemonic used to remember oxidation and reduction?

  The mnemonic is OIL RIG: Oxidation Is Loss, Reduction Is Gain.
• What happens during a redox reaction?


  Oxidation and reduction occur simultaneously.
• What is the reaction when iron reacts with dilute acid?

  Fe + 2HCl → Fe²⁺ + 2Cl⁻ + H₂
• What do iron atoms lose when they are oxidised?


  Iron atoms lose electrons.
• What do hydrogen ions gain during the reaction with iron?


  Hydrogen ions gain electrons.
• What is the general rule for displacement reactions?


  A more reactive metal will displace a less reactive metal from its compound.
• What happens when iron is placed in a solution of copper sulfate?


  Iron displaces copper, forming iron sulfate and copper metal.
• What is the ionic equation for the displacement of copper by iron?


  Fe → Fe²⁺ + 2e⁻ and Cu²⁺ + 2e⁻ → Cu
• What do ionic equations show?


  Ionic equations show only the particles that react and the products they form.
• What is the ionic equation for the reaction between magnesium and zinc ions?

  Mg + Zn²⁺ → Mg²⁺ + Zn
• What are spectator ions?

  Spectator ions are ions that do not change during the reaction.
• What are the steps to write an ionic equation for a displacement reaction?


  1. Write the full balanced equation.
  2. Identify and remove spectator ions.
  3. Show only the reacting particles and products.
• What is the full equation for the reaction of magnesium with zinc chloride?

  Mg + ZnCl₂ → MgCl₂ + Zn
• What is the equation for the reaction of zinc with iron(II) sulfate?

  Zn + FeSO₄ → ZnSO₄ + Fe
• What are the key concepts of redox reactions?

  • Oxidation is the loss of electrons.
  • Reduction is the gain of electrons.
  • They occur simultaneously in redox reactions.
  • Displacement reactions are a type of redox reaction.
• What does oxidation refer to in terms of electrons?


  Loss of electrons
• What does the acronym OIL RIG stand for in redox reactions?


  Oxidation Is Loss, Reduction Is Gain
• What are redox reactions?


  Reactions where oxidation and reduction take place
• In the reaction Mg + 2H₂O → Mg²⁺ + H₂, what happens to magnesium?


  Magnesium is oxidized
• What does it mean for a substance to be reduced in a chemical reaction?


  It gains electrons
• What is the general form of a displacement reaction?


  • A more reactive element displaces a less reactive element in a compound.
  • Example: Ca + FeSO₄ → CaSO₄ + Fe
• What do ionic equations show in a chemical reaction?


  Only the particles that take part in the reaction and change
• In the ionic equation Ca + Fe²⁺ + SO₄^2- → Ca²⁺ + Fe + SO₄^2-, what are the spectator ions?


  SO₄^2-
• How can you represent the individual half-equations for the reaction involving calcium and iron ions?

  Ca → Ca²⁺ + 2e^- and Fe²⁺ + 2e^- → Fe
• What is the half-equation for calcium losing electrons?


  Ca → Ca²⁺ + 2e^-
• What is the half-equation for iron gaining electrons?

  Fe²⁺ + 2e^- → Fe