Qhov sib txawv tseem ceeb ntawm chromate thiab dichromate yog tias chromate tshwm nyob rau hauv cov xim daj daj, whereas dichromate tshwm hauv cov xim txiv kab ntxwv ci.
Chromate thiab dichromate yog anions uas muaj chromium thiab oxygen atoms. Yog li ntawd, lawv yog oxyanions ntawm chromium. Peb feem ntau siv cov ntsiab lus no raws li cov ntsiab lus dav dav rau npe cov ntsiab lus uas muaj cov anions. Ob qho anions no muaj cov qauv tshuaj zoo sib xws; chromate muaj ib qho chromate anion thaum dichromate muaj ob chromate anions ua ke nrog ib leeg. Tab sis lawv muaj qhov sib txawv.
Chromate yog dab tsi?
Chromate yog ib qho oxyanion ntawm chromium uas muaj cov tshuaj formula CrO42-Feem ntau, peb siv lo lus no los sau cov lus sib txuas uas muaj cov anion sib sau ua ib pawg, piv txwv li cov tebchaw uas muaj chromate anion yog hu ua chromates. Feem ntau, cov chromates muaj xim daj daj. Lub chromium atom nyob rau hauv no anion yog nyob rau hauv +6 oxidation lub xeev. Nws yog ib qho muaj zog oxidizing tus neeg sawv cev. Cov molar loj ntawm no anion yog 115.99 g / mol.
Daim duab 01: Cov qauv tshuaj ntawm Chromate Ion
Thaum xav txog cov khoom thiab cov tshuaj tiv thaiv ntawm chromates, lawv tuaj yeem hnov mob nrog hydrogen peroxide vim tias peroxide anion hloov ib lossis ntau dua oxygen atoms. Hauv cov tshuaj aqueous, feem ntau muaj qhov sib npaug ntawm chromate thiab dichromate. Txawm li cas los xij, peb tuaj yeem pom cov nyiaj chromate siab ntawm pH qhov tseem ceeb (siab dua 6.5 pH) qhov twg cov nyiaj dichromate tsawg heev. Qhov no txhais tau tias, hauv cov tshuaj alkaline, cov hom tseem ceeb yog chromate.
Dichromate yog dab tsi?
Dichromate yog ib qho oxyanion ntawm chromium muaj cov tshuaj formula Cr2O72-Feem ntau, peb siv lo lus no los sau cov khoom sib txuas uas muaj cov anion sib sau ua ib pawg. Piv txwv li, potassium dichromate, sodium dichromate yog dichromates. Tsis tas li ntawd, cov tebchaw uas muaj dichromate raws li cov anion qhia cov xim txiv kab ntxwv ci. Molar mass ntawm no anion yog 215.99 g / mol. Thaum xav txog geometry ntawm dichromate, nws muaj tetrahedral geometry nyob ib ncig ntawm chromium atom.
Daim duab 02: Qhov tshwm sim ntawm Dichromate Compounds
Nyob rau hauv cov tshuaj aqueous, ib txwm muaj qhov sib npaug ntawm chromate thiab dichromate. Txawm li cas los xij, peb tuaj yeem pom cov dichromate ntau thiab tsawg heev ntawm chromate ntawm qhov pH qis (qis dua 6.5 pH).
Qhov txawv ntawm Chromate thiab Dichromate yog dab tsi?
Chromate thiab dichromate yog anions uas muaj chromium thiab oxygen atoms. Yog li ntawd, lawv yog oxyanions ntawm chromium. Qhov sib txawv tseem ceeb ntawm chromate thiab dichromate yog tias chromate tshwm nyob rau hauv cov xim daj daj, thaum dichromate tshwm hauv cov xim txiv kab ntxwv ci. Ntxiv mus, chromate ion muaj ib chromium atom ib anion thaum dichromate ion muaj ob chromium atoms ib anion.
Dhau li ntawd, qhov sib txawv ntxiv ntawm chromate thiab dichromate yog nyob rau hauv lawv cov molar mass. Cov molar loj ntawm dichromate anion yog 215.99 g / mol thaum molar loj ntawm chromate anion yog 115.99 g / mol. Hauv cov tshuaj aqueous, feem ntau muaj qhov sib npaug ntawm chromate thiab dichromate. Txawm li cas los xij, peb tuaj yeem pom cov nyiaj chromate siab ntawm pH qhov tseem ceeb (siab dua 6.5 pH) qhov twg cov nyiaj dichromate tsawg heev. Tab sis ntawm pH qis (qis dua 6.5 pH), muaj ntau dua dichromate ions.
Summary – Chromate vs Dichromate
Chromate thiab dichromate yog anions uas muaj chromium thiab oxygen atoms. Yog li ntawd, lawv yog oxyanions ntawm chromium. Qhov sib txawv tseem ceeb ntawm chromate thiab dichromate yog tias chromate tshwm hauv cov xim daj daj thaum dichromate tshwm hauv cov xim txiv kab ntxwv ci. Hauv cov tshuaj aqueous, feem ntau muaj qhov sib npaug ntawm chromate thiab dichromate. Txawm li cas los xij, peb tuaj yeem pom cov chromate ntau ntawm cov pH siab (siab dua 6.5 pH), thaum nyob hauv pH qhov tseem ceeb (qis dua 6.5 pH), muaj ntau dua dichromate ions.
