Izinombolo ze-oxidation, ama-ejenti e-redox nokulinganisa izigamu zokusabela

Yini irekhoda inombolo ye-oxidation

Inombolo ye-oxidation yishaji i-athomu elizoliphatha uma isibopho ngasinye phakathi kwama-athomu ahlukene siyi-ayoni ngokuphelele, ama-electron abiyelwe anikezwa i-athomu enamandla amakhulu e-electronegativity; ama-electron abiyelwe phakathi kwama-athomu afanayo ahlukaniswa ngokulinganayo. Ukubala okusemthethweni, hhayi ishaji elilinganisiwe. Emanzini, i-oxygen inikezwa −2 ne-hydrogen ngayinye +1, nakuba amashaji angxenye angempela emancane kakhulu.

I-oxidation ukukhula kwenombolo ye-oxidation, okuhambisana nokulahlekelwa ama-electron. I-reduction ukwehla kwenombolo ye-oxidation, ukuzuza ama-electron. Kokubili kwenzeka ndawonye njalo, ngoba ama-electron alahlwe uhlobo olulodwa kufanele azuzwe olunye. Kunoma yisiphi isibalo se-redox, ukukhula okuphelele kwenombolo ye-oxidation kulingana nokwehla okuphelele, futhi yonke indlela yokulinganisa incike kuloko kulingana.

Ukunikeza izinombolo ze-oxidation ngokulandelana kwenqubo

Sebenzisa imithetho kusukela ngenhla kohlu uye phansi. Lapho imithetho emibili iphikisana, ephakeme iyanqoba, futhi i-athomu yokugcina engaziwa kufomula ithola ngomehluko.

Ku-ayoni ye-dihydrogen phosphate, H₂PO₄⁻: 2(+1) + P + 4(−2) = −1, ngakho P = +5. Ku-ayoni ye-tetrathionate, S₄O₆²⁻: 4S + 6(−2) = −2, ngakho ama-athomu amane e-sulfur ahlangana abe ngu-+10 futhi isilinganiso singu-+2.5. Umphumela oyingxenye usho ukuthi ama-athomu esakhi esifanayo ahlala ezindaweni ezihlukene futhi inombolo ebikiwe iyisilinganiso. I-Magnetite, Fe₃O₄, inesilinganiso esingu-+8/3 ngoba iqukethe i-Fe²⁺ eyodwa ku-Fe³⁺ ezimbili ngazinye.

• I-athomu ku-sakhi esicwebile ingu-0 (Fe, O₂, S₈).
• I-ayoni enama-athomu ayodwa ilingana neshaji layo (Mg²⁺ ingu-+2, Br⁻ ingu-−1).
• Izinombolo ze-oxidation kufomula zihlangana zibe yishaji layo eliphelele.
• I-fluorine ingu-−1 kuzo zonke izinhlanganisela zayo.
• Izinsimbi zeqembu 1 zingu-+1 nezeqembu 2 zingu-+2 ezinhlanganiselweni.
• I-hydrogen ingu-+1 nama-nonmetal futhi −1 kuma-hydride ensimbi afana ne-NaH.
• I-oxygen ivame ukuba ngu-−2, kodwa −1 kuma-peroxide (H₂O₂), −½ kuma-superoxide (KO₂), futhi +2 ku-OF₂.
• I-chlorine, i-bromine ne-iodine zivame ukuba ngu-−1, ngaphandle uma zibophelelwe ku-oxygen noma ku-halogen elula.

Ukuqamba i-oxidizing agent ne-reducing agent

I-oxidizing agent yamukela ama-electron futhi yenza okunye kube ne-oxidation, ngakho yona iyehliswa. I-reducing agent inikela ngama-electron futhi yona ibe ne-oxidation. Qamba uhlobo lonke hhayi i-athomu eyodwa.

Cabanga ngo-2Fe²⁺(aq) + H₂O₂(aq) + 2H⁺(aq) → 2Fe³⁺(aq) + 2H₂O(l). I-iron ikhuphuka isuka ku-+2 iye ku-+3, ngakho i-Fe²⁺ ine-oxidation futhi iyi-reducing agent. I-oxygen yehla isuka ku-−1 ku-peroxide iye ku-−2 emanzini, ngakho i-H₂O₂ iyehliswa futhi iyi-oxidizing agent. I-hydrogen ihlala ingu-+1 yonke indawo. Ama-ayoni amabili e-iron ngalinye lilahlekelwa i-electron eyodwa kanti ama-athomu amabili e-oxygen e-peroxide ngalinye lizuza eyodwa, ngakho ama-electron amabili alahlekile futhi amabili azuzwa.

Uhlobo olulodwa lungadlala zombili izindima. Ku-Cl₂ + 2OH⁻ → Cl⁻ + ClO⁻ + H₂O, i-athomu eyodwa ye-chlorine isuka ku-0 iye ku-−1 kanti enye isuka ku-0 iye ku-+1. Lokhu kuyi-disproportionation, futhi i-Cl₂ iyi-oxidizing agent kanye ne-reducing agent.

Ukulinganisa izigamu zokusabela esixazululweni se-asidi

Ukwahlukanisa i-oxidation ne-reduction kukuvumela ukuthi ulinganise ukudluliswa kwama-electron ngakunye ngokwako, bese uhlanganisa izigamu ukuze ama-electron akhansele. Amanzi anikeza ama-athomu e-oxygen futhi u-H⁺ unikeza ama-athomu e-hydrogen ngoba yilezo zinhlobo ezikhona ngempela emanzini e-asidi.

Isibonelo esisebenzile 1. Ku-asidi, i-dichromate yenza i-nitrite ibe ne-oxidation: Cr₂O₇²⁻ + NO₂⁻ → Cr³⁺ + NO₃⁻. I-chromium isuka ku-+6 iye ku-+3 kanti i-nitrogen isuka ku-+3 iye ku-+5. Isigamu se-oxidation: NO₂⁻ + H₂O → NO₃⁻ + 2H⁺ + 2e⁻, neshaji elingu-−1 nhlangothi zombili. Isigamu se-reduction: Cr₂O₇²⁻ + 14H⁺ + 6e⁻ → 2Cr³⁺ + 7H₂O, neshaji elingu-+6 nhlangothi zombili. Ama-electron ayisithupha ahambisana nama-athomu amabili e-chromium ashintsha ngamayunithi amathathu ngalinye.

Phindaphinda isigamu se-oxidation ngo-3 ukuze izigamu zombili zibe nama-6e⁻, bese wengeza: Cr₂O₇²⁻ + 14H⁺ + 3NO₂⁻ + 3H₂O → 2Cr³⁺ + 7H₂O + 3NO₃⁻ + 6H⁺. Khansela u-6H⁺ no-3H₂O nhlangothi zombili: Cr₂O₇²⁻ + 8H⁺ + 3NO₂⁻ → 2Cr³⁺ + 3NO₃⁻ + 4H₂O. Hlola: Cr 2 no-2; N 3 no-3; O 7 + 6 = 13 no-9 + 4 = 13; H 8 no-8; ishaji −2 + 8 − 3 = +3 no-+6 − 3 = +3.

• Hlukanisa isibalo sesiphenguli sibe yisigamu se-oxidation nesigamu se-reduction.
• Linganisa wonke amasakhi ngaphandle kwe-O ne-H.
• Linganisa i-O ngokwengeza u-H₂O, bese ulinganisa i-H ngokwengeza u-H⁺.
• Linganisa ishaji ngokwengeza ama-electron ohlangothini oluhle kakhulu.
• Phakamisa izigamu ukuze ama-electron afane, uzengeze, bese ukhansela noma yini evela nhlangothi zombili.
• Hlola ama-athomu neshaji, futhi uqinisekise ukuthi akusali ama-electron.

Ukuguqula indlela yesixazululo sesisekelo

Esixazululweni sesisekelo, u-OH⁻ uningi futhi isibalo sokugcina akufanele siqukathe u-H⁺. Linganisa uthi isixazululo se-asidi, bese wengeza u-OH⁻ owanele nhlangothi zombili ukuze u-H⁺ ngamunye aphenduke amanzi. Ukwengeza uhlobo olufanayo nhlangothi zombili kugcina isibalo silinganisiwe.

Isibonelo esisebenzile 2. I-hypochlorite yenza i-chromium(III) hydroxide ibe ne-oxidation ibe yi-chromate esisekelweni: Cr(OH)₃ + ClO⁻ → CrO₄²⁻ + Cl⁻. I-chromium isuka ku-+3 iye ku-+6 kanti i-chlorine isuka ku-+1 iye ku-−1. Isigamu se-oxidation: Cr(OH)₃ + H₂O → CrO₄²⁻ + 5H⁺ + 3e⁻. Isigamu se-reduction: ClO⁻ + 2H⁺ + 2e⁻ → Cl⁻ + H₂O. Isiphindaphindi esijwayelekile esincane sika-3 no-2 singu-6, ngakho phindaphinda kabili isigamu sokuqala bese uphindaphinda kathathu esesibili.

Ukwengeza nokukhansela kunikeza 2Cr(OH)₃ + 3ClO⁻ → 2CrO₄²⁻ + 3Cl⁻ + 4H⁺ + H₂O. Engeza u-4OH⁻ nhlangothi zombili; ngakwesokudla, u-4H⁺ + 4OH⁻ uba ngu-4H₂O. Ekugcineni: 2Cr(OH)₃(s) + 3ClO⁻(aq) + 4OH⁻(aq) → 2CrO₄²⁻(aq) + 3Cl⁻(aq) + 5H₂O(l). Hlola: Cr 2 no-2; Cl 3 no-3; O 6 + 3 + 4 = 13 no-8 + 5 = 13; H 6 + 4 = 10 no-10; ishaji −7 nhlangothi zombili.

Amaphutha avamile ekubhaleni kwe-redox

Amaphutha amaningi e-redox angamaphutha okubhala, futhi ngalinye linokuhlola okuqondile.

Njengokuhlola kokugcina, qinisekisa ngezinombolo ze-oxidation kuphela ukuthi ama-electron alahlekile alingana nalawo azuziwe. Esibonelweni esisebenzile 2, ama-athomu amabili e-chromium ngalinye alahlekelwa ama-electron angu-3 (angu-6 sekukonke) kanti ama-athomu amathathu e-chlorine ngalinye azuza angu-2 (nawo angu-6).

• Ukuqamba i-athomu njenge-ejenti: bhala ukuthi i-Cr₂O₇²⁻ iyi-oxidizing agent, hhayi i-chromium.
• Ukubala ushintsho nge-athomu kodwa hhayi ngefomula: Cr₂O₇²⁻ → 2Cr³⁺ kuthatha ama-electron angu-6, hhayi angu-3.
• Ukubeka ama-electron ohlangothini olungafanele: angumkhiqizo esigamini se-oxidation futhi angezisabelo esigamini se-reduction. Uma ukuhlola ishaji kuhluleka, qala lapha.
• Ukulinganisa i-oxygen nge-O, O₂ noma O²⁻ esikhundleni sika-H₂O. Ama-ayoni e-oxide akhululekile awekho emanzini.
• Ukushiya u-H⁺ empendulweni yesixazululo sesisekelo, noma ukukhohlwa ukukhansela amanzi ngemva kokwengeza u-OH⁻.
• Ukucabanga ukuthi i-oxygen ihlala ingu-−2: hlola ama-peroxide, ama-superoxide nezibopho ze-O–F.
• Ukuxuba ukubhala: inombolo ye-oxidation ibhalwa uphawu kuqala (+3); ishaji le-ayoni libhalwa inombolo kuqala (3+).