left‑aligned, topic‑wise notes + memory tricks + 10 MCQ quiz
Oxidation and reduction are simultaneous but opposite processes. They always occur together. Oxidation and reduction changes are described in three principal ways.
1. Oxidation (oxygen addition / hydrogen removal)
Fe and Mg are oxidized; oxygen is reduced. Oxygen = oxidising agent; Fe, Mg = reducing agents.
CH₄ and HCl oxidized (O₂ and MnO₂ reduced). CH₄/HCl = reducing agents ; O₂/MnO₂ = oxidising agents.
2. Oxidation is loss of electron(s).
Copper is oxidized (acts as reducing agent).
3. Oxidation increases oxidation number.
1. Reduction = hydrogen addition / oxygen removal
Cl₂ and CuO are reduced (they are oxidising agents); H₂ is oxidized (reducing agent).
2. Reduction is gain of electron(s).
Fe³⁺, Mn⁷⁺ reduced → they are oxidising agents.
3. Reduction decreases oxidation number.
✔️ all examples from notes included: 4Fe+3O₂, 2Mg+O₂, CH₄+2O₂, 4HCl+MnO₂, Cu⁺/Cu²⁺, H₂+Cl₂, CuO+H₂, Fe³⁺/Mn⁷⁺ reductions.
• Redox always happens in pairs – one oxidised, one reduced.
• Identify changes in oxidation number: increase = oxidation ; decrease = reduction.
• Oxidising agent itself gets reduced (accepts electrons).
• Reducing agent itself gets oxidised (donates electrons).
• Memorise common pairs: O₂/oxide, halogens, KMnO₄ (Mn⁷⁺ → Mn²⁺).
• Practice with half‑reactions: write loss & gain separately.
• Left‑aligned notes help systematic reading – read twice daily.
• Use OIL RIG and LEO GER frequently.
click option → turns green if correct, red if wrong (others grey). then press ‘submit quiz’ to get score & answer key.