Qhov Tseem Ceeb - Ferrous vs Ferric
Iron yog ib qho ntawm cov hlau ntau tshaj plaws hauv ntiaj teb thiab Ferrous (Fe2+) thiab Ferric (Fe2+) yog ob hom oxidation ntawm lub caij hlau uas muaj qhov sib txawv raws li lawv cov khoom siv hluav taws xob. Ferrous muaj +2 oxidation xeev, thiab ferric muaj +3 oxidation xeev. Hauv lwm lo lus, lawv yog ob qhov ruaj khov ions los ntawm ib tus niam txiv keeb kwm. Qhov sib txawv tseem ceeb ntawm ob ions no yog lawv cov teeb tsa hluav taws xob. Ferrous ion yog tsim los tshem tawm 2d-electrons los ntawm hlau atom, whereas ferric ion yog tsim los ntawm tshem tawm 3d-electrons ntawm hlau atom. Qhov no muab cov khoom sib txawv, qhov sib txawv ntawm acidity, reactivity magnetic zog thiab, cov xim sib txawv hauv cov tshuaj complexes thiab cov kev daws teeb meem.
Ferrous yog dab tsi?
Ferrous hlau muaj +2 oxidation xeev; tsim los ntawm kev tshem tawm ob 3s-plhaub electrons los ntawm ib tug nruab nrab hlau atom. Hauv kev tsim cov hlau ferrous, 3d-electrons tseem zoo ib yam, qhov tshwm sim ion muaj tag nrho rau d-electrons. Ferrous ion yog paramagnetic vim nws muaj unpaired electrons nyob rau hauv lub plhaub sab nraud. Txawm li cas los xij, nws muaj tus lej ntawm d-electrons, thaum lawv sau rau hauv tsib d-orbitals qee cov electrons tseem tsis tau ua ke hauv ion. Tab sis thaum nws khi nrog lwm cov ligands, cov cuab yeej no tuaj yeem hloov pauv. Ferrous ions yog qhov yooj yim dua li ferric ions.
Ferric yog dab tsi?
Ferric hlau muaj +3 oxidation xeev; tsim los ntawm tshem tawm ob 3s-plhaub electrons thiab ib tug d-electron los ntawm ib tug nruab nrab hlau atom. Ferric hlau muaj 5d-electrons nyob rau hauv nws lub plhaub sab nrauv thiab qhov kev teeb tsa hluav taws xob no yog qhov ruaj khov vim muaj kev ruaj ntseg ntxiv los ntawm ib nrab ntawm cov orbitals. Ferric ions ntau acidic piv rau ferrous ions. Ferric ions tuaj yeem ua tus neeg sawv cev oxidising hauv qee cov tshuaj tiv thaiv. Piv txwv li, nws tuaj yeem oxidise iodide ions mus rau xim av tsaus yog tias iodine.
2Fe3+(aq) + 2I–(aq) → 2Fe2+(aq) + I2(aq/s)
Ferrous thiab Ferric txawv li cas?
yam ntxwv ntawm Ferrous thiab Ferric:
Electron Configuration:
Kev teeb tsa hluav taws xob ntawm hlau yog;
1s2, 2s2, 2p6, 3s 2, 3p6, 4s2, 3d6
Ferrous:
Ferrous hlau yog tsim tshem tawm ob lub electrons (ob 3s electrons) los ntawm hlau atom. Ferrous hlau muaj rau electrons hauv d-plhaub.
Fe → Fe2+ + 2e
Nws muaj lub teeb tsa hluav taws xob ntawm 1s2, 2s2, 2p6, 3s2, 3p6, 3d6.
Ferric:
Ferric hlau yog tsim tshem tawm peb lub electrons (ob 3s electrons thiab ib tug d-electron) los ntawm hlau. Ferric hlau muaj tsib electrons hauv d-plhaub. Qhov no yog ib nrab ntawm lub xeev nyob rau hauv d-orbitals uas yog suav hais tias yog ib tug kuj ruaj khov. Yog li ntawd, ferric ions kuj ruaj khov dua ferrous ions.
Fe → Fe3+ + 3e
Nws muaj lub teeb tsa hluav taws xob ntawm 1s2, 2s2, 2p6, 3s2, 3p6, 3d5.
Solubility hauv dej:
Ferrous:
Thaum ferrous ions nyob hauv dej, nws muab cov tshuaj ntshiab, tsis muaj xim. Vim tias, ferrous irons yog soluble hauv dej. Muaj ib qho me me ntawm Fe2+ hauv txoj kev dej ntuj.
Ferric:
Nws tuaj yeem paub meej meej thaum ferric (Fe3+) ions muaj nyob hauv dej. Vim hais tias, nws ua rau muaj yeeb yuj deposits nrog ib tug yam ntxwv saj rau dej. Cov sediments yog tsim vim ferric ions yog insoluble hauv dej. Nws yog qhov tsis kaj siab heev thaum ferric ions yaj hauv dej; tib neeg siv tsis tau dej uas muaj ferric ions.
Kev tsim kho nrog dej:
Ferrous:
Ferrous ion tsim ib txoj hauv kev nrog rau dej molecules; hu ua hexaaquairon(II) ion [Fe(H2O)62+ (aq). Nws yog xim daj ntseg ntsuab.
Ferric:
Ferric ion tsim ib txoj hauv kev nrog rau rau dej molecules; hu ua hexaaquairon(III) ion [Fe(H2O)63+ (aq). Nws yog liab doog hauv xim.
Tab sis, feem ntau peb pom cov xim daj daj hauv dej; Qhov no vim yog tsim los ntawm lwm cov hydro-complex, hloov protons rau dej.
Image Courtesy: 1. "Iron(II) oxide" [Public Domain] via Commons 2. "Iron(III)-oxide-sample" by Benjah-bmm27 - Tus kheej ua haujlwm. [Public Domain] via Commons
