Okusayidi chromium

mankhwala mankhwala angapo wopangidwa mwa zinthu ziwiri yosavuta - Kr ndi O, - a gulu la mankhwala zochita kupanga - oxides. dzina lawo wamba - chromium oxide anatengedwa mopitirira mu parentheses mawerengero achiroma amasonyeza valence wa zitsulo. maina ena ndi mankhwala mitunduyi awo:

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

pawiri A imene shestivalenten zitsulo ndi kukhala okusayidi apamwamba a chromium. Izi olimba, odorless, m'maonekedwe ngati mdima yofiira makhiristo (mu mlengalenga, iwo anayala chifukwa amphamvu hygroscopic). Molar kulemera - 99,99 g / Mole. Osalimba pa 20 ° C wofanana 2,70 g / cm³. Limatsogolera mfundo - 197 ° C, kuwira - 251 ° C. Pa 0 ° C mu madzi kusungunuka 61,7 g / 100 pa 25 ° C - 63 g / 100 ml pa 100 ° C - 67,45 g / 100 ml. okusayidi nazonso kusungunuka asidi sulfuric (chromic osakaniza, umene unali ntchito zasayansi osamba mankhwala mbale) ndi asidi nitric, Mowa, ethyl efa, asidi acetic, acetone. Pa 450 ° C linawola kuti Cr2O3.

Chromium (VI) okusayidi ntchito ndondomeko ya electrolysis (kwa chromium koyera) kwa chromating mankhwala nthaka, electrolytic plating, monga amphamvu wothandizila oxidizing (kwa kupanga enaake, isatin). Apamwamba chromium okusayidi ntchito kupeza mowa mpweya wotuluka tikamapuma. Zimene anapeza malinga chiwembu: 4CrO3 + 6H2SO4 + 3C2H5OH → 2Cr2 (SO4) 3 + 3CH3COOH + 9H2O. Pamaso pa mowa amasonyeza kusintha njira mtundu (akutembenukira obiriwira).

Chromium (VI) okusayidi, komanso onse hexavalent Kr, ndi amphamvu poizoni (woopsa mlingo - 0,1 g). Chifukwa cha ntchito yake yapamwamba CrO3 amachititsa poyatsira (ndi mabomba) organic zinthu , anakumana nawo. Ngakhale osakhalitsa otsika, ndi apamwamba a okusayidi chromium ndi oopsa ngati Mpweya, monga khansa ya m'mapapo. Pa kukhudzana ndi khungu (ngakhale kuchotsedwa posachedwapa) zimapangitsa kuyabwa, dermatitis, chikanga, amakwiya chitukuko cha khansa.

Tetravalent chromium okusayidi ndi CrO2 maonekedwe ndi olimba mu mawonekedwe a mibulu wakuda tetrahedral ferromagnetic. okusayidi Chromium ali misa molar 4 83.9949 g / mol, kachulukidwe 4,89 g / cm³. mankhwala chimasungunula imodzi decomposing, pa kutentha 375 ° C. madzi si kupasuka. Agwiritsidwa ntchito atolankhani maginito kujambula monga thunthu ntchito. Ndi kutchuka kwa CD-ROM ndi DVD-ROM pagalimoto ntchito chromium (IV) okusayidi utachepa. Choyamba apanga mu 1956 ndi sayansi ku EI DuPont kampani Norman L. Cox ndi kuwonongeka kwa chromium trioxide pamaso pa madzi pa kutentha 640 ° C ndi mavuto 200 MPa. Malinga DuPont chilolezo wosindikiza Sony ku Japan ndipo BASF ku Germany.

3 chromium okusayidi Cr2O3 ndi zabwino-grained olimba zinthu kuwala mdima wobiriwira. Molar misa liri 151,99 g / mol. Kachulukidwe - 5,22 g / cm³. Limatsogolera mfundo - 2435 ° C, otentha - 4000 ° C. The refractive index zinthu oyera - 2.551. okusayidi Izi si sungunuka mu madzi, mowa, acetone, acid. Monga njira osalimba a corundum osalimba, ndi kutumikiridwa mu formulations kupukuta wothandizila (mwachitsanzo, muiike GOI). Ichi ndi chimodzi mwa oxides zoyambirira za chromium, amene ntchito ngati pigment a. Kwa nthawi yoyamba pa luso chinsinsi izo analandiridwa mu 1838 mu mawonekedwe a mandala hydrated mawonekedwe. Mu chikhalidwe, zopezeka mu mawonekedwe a chrome chitsulo miyala FeO • Cr2O3.

Divalent chromium okusayidi - olimba wakuda kapena wofiira mtundu ndi mfundo limatsogolera wa 1550 ° C. Chimasungunula ndi kuwonongeka. Molar kulemera - 67,996 g / mol. okusayidi Chromium (II) a mtundu wofiira si pyrophoric, ndi chinthu chomwecho ndi wakuda pyrophoric. Ufa uyatsa zokha mu mlengalenga, kotero izo zikhoza kusungidwa yekha pansi wosanjikiza wa madzi, monga zilibe kucheza ndi izo. Black okusayidi wa chromium zovuta kupeza mu mawonekedwe woyera.

Pakuti okusayidi chromium kuchepetsa valence lililonse katundu pamoyo, ndipo kwa okusayidi ndi valence apamwamba - acid.