[{"data":1,"prerenderedAt":111},["ShallowReactive",2],{"cheatsheet-main-group-chemistry":3},{"sheet":4},{"sheetSlug":5,"topicSlugs":6,"primaryTopic":7,"title":8,"subtitle":9,"sections":10},"main-group-chemistry",[5],29,"Main-Group Chemistry","Periodic trends, group reactivity, allotropes, hydrogen, and the key industrial processes.",[11,23,31,39,47,55,63,71,79,87,95,103],{"heading":12,"kind":13,"items":14},"Metallic character & ion charge","rules",[15],{"ref":16,"mode":19,"provenance":20,"text":21,"source_hash":22},{"type":17,"topic":7,"id":18,"field":17},"rule","MG-R001","transform","original","Metallic character rises down a group, falls left-to-right across a period. The group number gives the characteristic ion charge (group 1 → 1+, group 2 → 2+, group 17 → 1−).","3c07705d04922b4548307b49214b7201e821043f7961caef92885db5297aef4e",{"heading":24,"kind":13,"items":25},"Group reactivity",[26],{"ref":27,"mode":19,"provenance":20,"text":29,"source_hash":30},{"type":17,"topic":7,"id":28,"field":17},"MG-R002","Alkali and alkaline-earth reactivity increases down the group (the valence electron is held more loosely). Group 1 is more reactive than group 2 in the same period.","c31d6954a8a7b92102b8c62ed88465c920505db57914346d87845b62d0af6ae1",{"heading":32,"kind":13,"items":33},"Periodic trends for ranking",[34],{"ref":35,"mode":19,"provenance":20,"text":37,"source_hash":38},{"type":17,"topic":7,"id":36,"field":17},"MG-R003","Atomic radius increases down a group, decreases across a period; ionization energy and electronegativity do the opposite (down ↓, across ↑).","ef1d47b5cff8792465fff5261c1d0c350202891cf5c757aebfd64e15bbc04b46",{"heading":40,"kind":13,"items":41},"Metals + water",[42],{"ref":43,"mode":19,"provenance":20,"text":45,"source_hash":46},{"type":17,"topic":7,"id":44,"field":17},"MG-R004","Group 1: 2M + 2H₂O → 2MOH + H₂ (all, cold water). Group 2 varies: Be none; Mg slow in hot water (steam → MgO + H₂); Ca, Sr, Ba: M + 2H₂O → M(OH)₂ + H₂. More vigorous for lower, larger metals.","1c826ac83f378058c8b95f97e3560582a3f7e5f7b5d57954d49de0c07841f763",{"heading":48,"kind":13,"items":49},"Metals + oxygen / halogens",[50],{"ref":51,"mode":19,"provenance":20,"text":53,"source_hash":54},{"type":17,"topic":7,"id":52,"field":17},"MG-R005","With O₂: Li → Li₂O, Na → Na₂O₂ (peroxide), K/Rb/Cs → KO₂ (superoxide); group 2 → oxide MO (heavier ones, esp. Ba, form peroxide MO₂ when heated in excess O₂). With halogens → the ionic halide (2Na + Cl₂ → 2NaCl).","30ab6453945a5e09ce16dda8fbaab64e9f22922c362d81279b725447a15672ef",{"heading":56,"kind":13,"items":57},"Allotropes",[58],{"ref":59,"mode":19,"provenance":20,"text":61,"source_hash":62},{"type":17,"topic":7,"id":60,"field":17},"MG-R006","Structure drives properties: graphite (sp² layers → soft, conductive) vs diamond (sp³ network → hard, insulating); white P (strained P₄ → reactive) vs red P (polymeric → stable).","3e82da964938579c138fcc47be6a138a588a1d937e475ba27e894c6c09c41bb3",{"heading":64,"kind":13,"items":65},"Hydrogen behavior",[66],{"ref":67,"mode":19,"provenance":20,"text":69,"source_hash":70},{"type":17,"topic":7,"id":68,"field":17},"MG-R007","Hydrogen is a reducing agent: +1 with a more electronegative nonmetal, −1 in ionic metal hydrides. H₂ reduces less-active metal oxides; an ionic hydride + water → metal hydroxide + H₂.","a3b0af717621d33b4271170865700cb10039d8e848251a315837a25765c11f88",{"heading":72,"kind":13,"items":73},"Preparing hydrogen",[74],{"ref":75,"mode":19,"provenance":20,"text":77,"source_hash":78},{"type":17,"topic":7,"id":76,"field":17},"MG-R008","Water-gas (C + H₂O → CO + H₂), steam reforming of hydrocarbons, electrolysis of water (2H₂O → 2H₂ + O₂), and active metal + acid (Fe + 2H⁺ → Fe²⁺ + H₂).","6e5977495183a73d29ad4bca4b0fafd445c16fbba421beeca9ea7f6aa4679e0d",{"heading":80,"kind":13,"items":81},"Haber-Bosch (ammonia)",[82],{"ref":83,"mode":19,"provenance":20,"text":85,"source_hash":86},{"type":17,"topic":7,"id":84,"field":17},"MG-R009","N₂ + 3H₂ ⇌ 2NH₃ (ΔH° ≈ −92 kJ), iron catalyst. Exothermic with fewer gas moles, so high pressure and low temperature favor NH₃ at equilibrium; a moderate temperature is a kinetic/yield compromise (speed over yield).","c07045230652484d928d706492dda441626925ccf411e6d4e69cb1cbf81677e8",{"heading":88,"kind":13,"items":89},"Ostwald (nitric acid)",[90],{"ref":91,"mode":19,"provenance":20,"text":93,"source_hash":94},{"type":17,"topic":7,"id":92,"field":17},"MG-R010","Oxidize ammonia in stages: 4NH₃ + 5O₂ → 4NO + 6H₂O; 2NO + O₂ → 2NO₂; 3NO₂ + H₂O → 2HNO₃ + NO.","e7fb9c65a71c9128f80d9507a6e726042b4a66af68eb968cec0f1430fda61bfa",{"heading":96,"kind":13,"items":97},"Contact (sulfuric acid)",[98],{"ref":99,"mode":19,"provenance":20,"text":101,"source_hash":102},{"type":17,"topic":7,"id":100,"field":17},"MG-R011","2SO₂ + O₂ ⇌ 2SO₃ over V₂O₅; absorb SO₃ into H₂SO₄ to make oleum, then dilute to H₂SO₄. Higher pressure and lower temperature favor SO₃.","ff0559c87f90b43db149063a610638cceda9c57c2c5594fbd9d27883005ae7f4",{"heading":104,"kind":13,"items":105},"Metallurgy",[106],{"ref":107,"mode":19,"provenance":20,"text":109,"source_hash":110},{"type":17,"topic":7,"id":108,"field":17},"MG-R012","Very active metals come from electrolysis of a molten salt: Downs cell (2NaCl → 2Na + Cl₂), Hall-Héroult (alumina in molten cryolite → Al). Less-active metals come from chemical reduction.","896ff806f828bd8008091dd7a9e419e09566a62efb8af7e4156fdbcaec7fb132",1787246033206]