[{"data":1,"prerenderedAt":105},["ShallowReactive",2],{"cheatsheet-redox-reactions-and-redox-balancing":3},{"sheet":4},{"sheetSlug":5,"topicSlugs":6,"primaryTopic":7,"title":8,"subtitle":9,"sections":10},"redox-reactions-and-redox-balancing",[5],7,"Redox Reactions & Balancing","Oxidation numbers, identifying redox and agents, disproportionation, and the half-reaction and oxidation-number methods.",[11,23,31,39,47,55,63,72,81,89,97],{"heading":12,"kind":13,"items":14},"Assigning oxidation numbers","rules",[15],{"ref":16,"mode":19,"provenance":20,"text":21,"source_hash":22},{"type":17,"topic":7,"id":18,"field":17},"rule","ROX-R001","transform","original","Free element = 0. Monatomic ion = its charge. F = −1. H = +1 (but −1 in metal hydrides). O = −2 (−1 in peroxides, +2 in OF₂). Fixed-charge metals: Group 1 = +1, Group 2 = +2, Al = +3. Variable-charge metals (Sn, Pb, Tl, transition metals): use the Roman numeral or solve with the sum rule.","87eaacf8a9f15f592203bfbf1548c9525a3587cf9a6b9a3bdf11c2dbccaf8735",{"heading":24,"kind":13,"items":25},"Sum rule (solve for an unknown)",[26],{"ref":27,"mode":19,"provenance":20,"text":29,"source_hash":30},{"type":17,"topic":7,"id":28,"field":17},"ROX-R002","Oxidation numbers sum to 0 (neutral compound) or to the charge (polyatomic ion). Solve algebraically: H₂SO₄ → S = +6; MnO₄⁻ → Mn = +7.","756bc17b569a1ea256065aad4e82556aebf12784776a61ff0fbc8a8dc3faf304",{"heading":32,"kind":13,"items":33},"Average oxidation numbers",[34],{"ref":35,"mode":19,"provenance":20,"text":37,"source_hash":38},{"type":17,"topic":7,"id":36,"field":17},"ROX-R003","A formula-unit average can be fractional and is bookkeeping, not a per-atom state: Fe₃O₄ → Fe = +8/3; S₂O₃²⁻ → S = +2 (avg); S₄O₆²⁻ → S = +2.5 (avg).","61c1eba221f3f8092521d83c5bd6cb43da28fa29efca27e8b9db621e867adc50",{"heading":40,"kind":13,"items":41},"Redox or not?",[42],{"ref":43,"mode":19,"provenance":20,"text":45,"source_hash":46},{"type":17,"topic":7,"id":44,"field":17},"ROX-R005","Assign oxidation numbers on both sides. If any element's number changes → redox (name it). If none change → not redox (neutralization, metathesis, hydrolysis).","d9711280a42b2870d45ccb05062c9f12757beba638c65e50958725ed95c295b1",{"heading":48,"kind":13,"items":49},"Oxidized / reduced / agents",[50],{"ref":51,"mode":19,"provenance":20,"text":53,"source_hash":54},{"type":17,"topic":7,"id":52,"field":17},"ROX-R006","Oxidized = number increases (loses e⁻). Reduced = number decreases (gains e⁻). Oxidizing agent = the whole species reduced; reducing agent = the whole species oxidized. Name the full formula (HNO₃, not N).","3c8d2178f8ed7a63f942737a714e89d6cc31630c3c0deeacf68b2324caf15e21",{"heading":56,"kind":13,"items":57},"Disproportionation & comproportionation",[58],{"ref":59,"mode":19,"provenance":20,"text":61,"source_hash":62},{"type":17,"topic":7,"id":60,"field":17},"ROX-R007","Disproportionation: one element is both oxidized and reduced (2H₂O₂ → 2H₂O + O₂). Comproportionation: two states of one element converge to one (NH₄NO₃ → N₂O + 2H₂O).","da0880064f95405f068939a1b985a594570868a1244277d4f9dfa123b87455b9",{"heading":64,"kind":65,"items":66},"Non-redox traps","pitfalls",[67],{"ref":68,"mode":19,"provenance":20,"text":70,"source_hash":71},{"type":17,"topic":7,"id":69,"field":17},"ROX-R008","Looks like redox but isn't (no ox-number change): halide/phosphide hydrolysis (PCl₅ + 4H₂O → H₃PO₄ + 5HCl), peroxide preservation, and acid-base neutralization. Check every element first.","4c7c305da2b89a9b96614081bee60c94bb26d2939d0958a3d8eca3eea0c33c7e",{"heading":73,"kind":74,"items":75},"Half-reaction method (acidic)","steps",[76],{"ref":77,"mode":19,"provenance":20,"text":79,"source_hash":80},{"type":17,"topic":7,"id":78,"field":17},"ROX-R009","Split into two half-reactions; balance non-H/O atoms; balance O with H₂O; balance H with H⁺; balance charge with e⁻ (e⁻ on right = oxidation, on left = reduction); scale to equal e⁻; add and cancel.","95aa6a1a9bcec18c4b989d2d369db7745fcf72a4d7a50213715aedc84110d9b5",{"heading":82,"kind":74,"items":83},"Half-reaction method (basic)",[84],{"ref":85,"mode":19,"provenance":20,"text":87,"source_hash":88},{"type":17,"topic":7,"id":86,"field":17},"ROX-R010","Balance as if acidic, then add one OH⁻ to both sides for each H⁺; combine H⁺ + OH⁻ → H₂O; cancel duplicate H₂O. The final answer has OH⁻ and H₂O but no H⁺.","fef543de8cff9b7ba24b1c2ffdb352552d6c1332f8670ff0061b7a40d36e36a3",{"heading":90,"kind":13,"items":91},"Match the electrons",[92],{"ref":93,"mode":19,"provenance":20,"text":95,"source_hash":96},{"type":17,"topic":7,"id":94,"field":17},"ROX-R012","Electrons transferred must be equal in both halves: scale each to the LCM of the two counts (2 & 3 → 6). After summing, electrons must cancel completely; leftover e⁻ means the multipliers are wrong.","6d98eb6a55190c14f84d4be7adbfef22cf4903303676387aadc37dd04496c041",{"heading":98,"kind":74,"items":99},"Oxidation-number method (non-aqueous)",[100],{"ref":101,"mode":19,"provenance":20,"text":103,"source_hash":104},{"type":17,"topic":7,"id":102,"field":17},"ROX-R013","Assign ox numbers; find electrons lost (reducing agent) and gained (oxidizing agent); scale by the LCM so total lost = total gained; balance the rest by inspection; reduce. Best when no H⁺/OH⁻/H₂O is needed.","4ba140c158a97877a946df943fe8dbe8d65c6e9c86bf993df1b49a76b63bdf95",1787246033278]