Chromium oxide

Eziliqela iikhompawundi chemical ezibandakanya izinto ezimbini ezilula - Kr no O, - lilungu udidi iikhompawundi ezingaphiliyo - oxides. igama zawo ezifanayo - oxide chromium, kuthathwa kwindawo yegama Amanani baseRoma zibonisa Valence le sentsimbi. Amanye amagama kunye neefomula yemizimba yethu:

• chromium (II) oxide - chromium oxide, CrO;
• chromium (III) oxide - chromic eluhlaza, sesquioxide chromium, Cr2O3;
• chromium (IV) oxide - oxide chromium, CrO2;
• chromium (VI) oxide - chromic acetic, chromium trioxide, CrO3.

A ezimbaxa apho shestivalenten yesinyithi kwaye oxide ephezulu of chromium. Oku eqinileyo, esha, ngembonakalo njenge ziikristale ezimnyama-ezibomvu (emoyeni, bathi saa ngenxa hygroscopic onamandla). ubunzima izinyo - 99,99 g / nolovane. Density kwi-20 ° C ilingana 2.70 g / cm³. Lokunyibilika - 197 ° C, zokupheka - 251 ° C. Xa 0 ° C emanzini onyibilikisiweyo 61,7 g / 100 kwi-25 ° C - 63 g / ml 100 kwi-100 ° C - 67,45 g / 100 ml. Le oksayidi kwakhona unyityilikiswa sulphuric acid (chromic lo mxube, eyasetyenziswa kwi yilebhu chemical ahlambe izitya) kunye ne-nitric acid, ethanol, ethyl iEtere, acetic acid, acetone. 450 ° C abole ku Cr2O3.

Chromium (VI) oxide lisetyenziswa kwinkqubo electrolysis (ngokuba chromium esulungekileyo) ngenxa chromating iimveliso nezinki, nesingxobo electrolytic, njenge-arhente oxidizing eyomeleleyo (ekuveliseni indigo, isatin). Higher chromium oksayidi isetyenziswa lokufumana utywala umoya. Efunyenweyo asabela ngokutsho scheme: 4CrO3 + 6H2SO4 + 3C2H5OH → 2Cr2 (SO4) 3 + 3CH3COOH + 9H2O. Ubukho utywala lubonisa utshintsho isisombululo umbala (Ijika luhlaza).

Chromium (VI) oxide, kwakunye nazo zonke hexavalent Kr, kukho ityhefu esinamandla (ithamo ebulalayo - 0.1 g). Ngenxa yokuba umsebenzi yalo phezulu CrO3 ibangela ucinezelo (kunye udubulo) izinto eziphilayo , badibene nabo. Nangona lokungazinzi ephantsi, kungona oxide chromium kuyingozi ukuba arhogelwe, njengoko umhlaza wemiphunga. Phezu udibana nesikhumba (ukuba luthe lwancothulwa kungekudala) ebangela ukutyabuka, dermatitis, nangokhwekhwe, kuphakamisa umhlaza.

Tetravalent chromium oxide ne CrO2 Imbonakalo isiqina ngohlobo ziikristale abamnyama tetrahedral ferromagnetic. Chromium oksayidi enobunzima izinyo ka 4 83.9949 g / Mol, ingxinano 4,89 g / cm³. Le into linyibilike ngaxeshanye okubolileyo, kubushushu ka-375 ° C. Amanzi akumele kubenze. Oku ezisetyenziswa eendaba iinkcukacha ngemagnethi lokurekhoda nomongo ukusebenza. Ngenxa ukuthandwa CD-ROM kunye DVD-ROM drive ukusebenzisa chromium (IV) oxide zehla. Ekuqaleni kuhlelwe ngo-1956 yi ekhemesti evela kwinkampani EI Dupont Norman L. Cox ngenxa yokubola chromium trioxide phambi zamanzi lobushushu 640 ° C kwakunye noxinzelelo 200 MPA. Ngokutsho Dupont ilayisenisi ekhutshwe Sony eJapan BASF eJamani.

3 chromium oxide Cr2O3 kuyinto material entle-olungisiweyo esiqinileyo ekukhanyeni ukuya esiluhlaza bumnyama. mass izinyo ilingana 151,99 g / Mol. Density - 5.22 g / cm³. Lokunyibilika - 2435 ° C, ukubilisa - 4000 ° C. I zokunganyangeki Isalathisi ukwimo ecocekileyo - 2.551. Le oxide ayikho enyibilikayo emanzini, utywala, acetone, acid. njengoko siwungena lexinene corundum ukuxinana, oko ibhalwa nemixube ipolishi arhente (umz, cola GOI). Le yenye oxides esisiseko ye chromium, esetyenziswa sombala. Kuba okokuqala kwiteknoloji emfihlekweni ngayo yafunyanwa ngo-1838 ngokohlobo ifomu ngaphaya hydrated. Kwindalo, eyafunyanwa ngokohlobo chrome yentsimbi ekrwada feo • Cr2O3.

Divalent chromium oksayidi - okuqinileyo umbala omnyama okanye obomvu kunye indawo yokunyibilika ka 1550 ° C. Linyibilike nge yokubola. ubunzima izinyo - 67,996 g / Mol. Chromium oxide (II) Umbala obomvu ayikho pyrophoric, kwaye ukwimo enye i pyrophoric emnyama. Powder avuse ngokuzenzekelayo umoya, ngoko ke kunokugcinwa kuphela phantsi umaleko yamanzi, njengoko akuthethi ukusebenzisana nayo. Black oxide of chromium kunzima kakhulu ukufumana ngendlela ecocekileyo.

Kuba chromium oxide ne Valence ephantsi iimpawu ezingundoqo oluqhelekileyo, nangenxa oxide kunye Valence aphezulu - acid.