Oxidation and Reduction

50 lessons, pages 1201–1250.

  1. Recognising Oxidation and Reduction — A reaction class identified by linked changes in oxidation and reduction
  2. Oxidation as Addition of Oxygen — The historical oxygen-based description and its useful limits
  3. Reduction as Removal of Oxygen — Interpreting metal-oxide conversion and oxygen transfer
  4. Hydrogen Transfer in Redox — Hydrogen loss as oxidation and hydrogen gain as reduction in suitable reactions
  5. Why Oxidation and Reduction Occur Together — Conservation of electrons or transferred atoms across a complete reaction
  6. Electron Loss Defines Oxidation — Tracking electrons released when an atom or ion forms a higher-charge ion
  7. Electron Gain Defines Reduction — Tracking electrons accepted when an ion becomes less positively charged
  8. Electron Transfer in Metal Displacement — A metal atom reducing another metal's aqueous ion
  9. Oxidising Agents — The electron acceptor is itself reduced while oxidising another species
  10. Reducing Agents — The electron donor is itself oxidised while reducing another species
  11. Assigning Both Agents in a Reaction — A reliable species-by-species method for naming oxidant and reductant
  12. Half-Reactions as Electron Bookkeeping — Separating electron loss and gain without mistaking a half-reaction for an isolated process
  13. Balancing Simple Metal–Ion Half-Reactions — Using electron coefficients to conserve both charge and atoms
  14. Combining Simple Half-Reactions — Equalising electrons before adding oxidation and reduction statements
  15. Spectator Ions in Redox Equations — Distinguishing reacting ions from unchanged aqueous counterions
  16. Ionic Charges and Electron Counts — Inferring electron gain or loss from a specified change in ion charge
  17. Oxidation Numbers as a Tracking Tool — Formal assignments that identify redox even without free ions
  18. Oxidation Number of an Element — Zero in a free elemental substance, including diatomic elements
  19. Oxidation Number and Monatomic Ion Charge — Equating a single-atom ion's formal oxidation number with its charge
  20. The Sum Rule for Neutral Compounds — Calculating an unknown oxidation number from a zero total
  21. The Sum Rule for Polyatomic Ions — Calculating an unknown oxidation number from overall ionic charge
  22. Usual Oxidation Numbers of Group 1 and 2 — Applying +1 and +2 conventions in introductory compounds
  23. Usual Oxygen Oxidation Number and Exceptions — Using −2 carefully with peroxides and oxygen–fluorine compounds
  24. Usual Hydrogen Oxidation Number and Hydrides — Distinguishing hydrogen with nonmetals from metal hydrides
  25. Halogen Oxidation Numbers — Using −1 for common halides while recognising oxygen-containing exceptions
  26. Finding Carbon Oxidation Number — Using simple carbon compounds to track formal carbon change
  27. Finding Sulfur Oxidation Number — Comparing sulfide, sulfur dioxide and sulfate by the sum rule
  28. Finding Nitrogen Oxidation Number — Comparing ammonia, elemental nitrogen and nitrate by the sum rule
  29. Oxidation-Number Increase and Decrease — Identifying which element is oxidised and which is reduced
  30. Oxidation Number Is Not Always Ionic Charge — Formal electron assignment versus measured charge distribution
  31. Redox in Metal–Acid Reactions — Metal oxidation coupled to reduction of hydrogen ions
  32. Redox in Metal–Water Reactions — Metal oxidation coupled to hydrogen formation under suitable conditions
  33. Redox in Metal Oxide Reduction — Oxygen removal and reductant oxidation in extraction examples
  34. Redox in Combustion — Fuel oxidation coupled to reduction of oxygen
  35. Redox in Halogen Displacement — Halogen molecules and halide ions exchanging electron ownership
  36. Redox and the Reactivity Series — Using relative metal reactivity to predict simple displacement
  37. Redox Versus Acid–Base Reaction — Checking oxidation-number changes instead of relying on reaction labels
  38. Redox Versus Precipitation — Ionic rearrangement without electron-transfer bookkeeping
  39. No-Change Cases and Redox Identification — Testing every element before claiming oxidation or reduction
  40. Redox Evidence and Observable Changes — Interpreting color, deposits and gas cautiously alongside equations
  41. Corrosion as a Redox Process — Iron oxidation and oxygen reduction in moist environments
  42. Preventing Corrosion by Barriers — How coatings interrupt contact with oxygen and water
  43. Sacrificial Protection of Iron — A more reactive metal oxidising preferentially
  44. Redox in Batteries: A First Look — Separating paired redox changes so electrons can travel in a circuit
  45. Redox in Bleaching and Disinfection — Oxidants changing molecules while concentration and conditions matter
  46. Redox in Living Systems — Controlled oxidation of fuels and reduction of oxygen in respiration
  47. Electron Balance as a Reaction Check — Matching oxidation and reduction electron counts in simple equations
  48. Common Redox Errors and Corrections — Avoiding agent-label, charge and oxidation-number mistakes
  49. Mixed Redox Classification Practice — Classifying varied reactions with complementary redox viewpoints
  50. Oxidation and Reduction Unit Review — Connecting oxygen, hydrogen, electrons, agents and oxidation numbers