I-oxalic acid

I-dibasic acid enomkhawulo we-carboxylic ne-formula eqondile C2H2O4 ibizwa ngokuthi yi-nomenclature ehlelekile, i-ethanedioic acid. Lezi zinto ziyaziwa ngaphansi kwesinye, igama elivamile - i-oxalic acid. Yatholwa okokuqala ngesazi samakhemikhali waseJalimane F. Weller esivela ku-cyanogen (dinitrile oxalic acid) ngo-1824. Amakhemikhali angenambala we-asidi ahlakazeka emanzini ukuze enze izixazululo ezingenambala. Ubuningi be-molar bungu-90.04 g / mol. Ekubukeni kubonakala sengathi i-crystal monoclinic engenambala. Ngesikhathi sokushisa kwe-20 ° C, u-8 g we-oxalic acid uhlakaza ku-100 g wamanzi. Ihlakaza kahle i-acetone, i-ethyl yotshwala nesulfure ether. Ubukhulu bayizi-1.36 g / cm³. Iyancibilika ekushiseni kwe-189.5 ° C, i-sublimated ngo-125 ° C, idilika ku-100-130 ° C.

Zonke izici zamakhemikhali isici se-carboxylic acid esine-oxalic acid. I-formula yayo: NOOS-COOH. Naphezu kokuthi libhekisela kuma-acids carboxylic, kubhekwe njengama-acid aqinile (izikhathi ezingu-3000 ezinamandla kune-acetic acid): C2O4H2 → C2O4H- + H + (pK = 1.27) nokuqhubeka: C2O4H- → C2O42 - + H + (pK = 4.27). Ama-Esters namanoni ale-asidi abizwa ngokuthi ama-oxalates. I-oxalate ion C2O42- iyisenti esinciphisa. Uma i-oxalic acid iphendula ngesisombululo se-potassium permanganate (i-KMnO4), lokhu kunciphisa futhi ikhambi lichazwe. Kubonakala ngokuphendula okuguquguqukayo nokuphuza ngokuphuza utshwala (esterification), okuholela ekusungulweni kwe-esters: HOOC-COOH + 2HOR ↔ 2H2O + ROOC-COOR.

Embonini, i-oxalic acid iyatholakala nge-oxidizing chemical compounds. Isibonelo, phambi kwe-catalyst ye-vanadium (V2O5), ingxube ye-nitric (HNO3) ne-sulfuric (H2SO4) acids oxidizes utshwala, ama-carbohydrate nama-glycols. Indlela yokwenza i-ethylene ne-acetylene nge-nitric acid (i-HNO3) phambi kwe-palladium usawoti Pd (NO3) 2 noma i-PdCl2 nayo isetshenziswa. I-oxalic acid itholakala ku-propylene, ehlanganiswa ne-nitrogen dioxide (NO2). Kukhona ithemba elihle lokukhiqizwa kwe-asidi ngokusebenzisana kwe-sodium hydroxide (NaOH) ne-carbon monoxide (CO) ngesigaba esiphakathi sokwakhiwa kwe- sodium: NaOH + CO → HCOONa. Khona-ke i-oxalate ye-sodium yenziwa futhi i-hydrogen ikhululiwe: i-HCOONa + NaOH → i-NaOOC-COONa + H2 ↑. Kusuka ku-oxalate ye-sodium ngendlela e-acidic, i-oxalic acid iyatholakala: i-NaOOC-COONa + 2H + → HOOC-COOH + 2Na +.

Imikhakha esemqoka yokusetshenziswa kwe-oxalic acid ihlanza noma i-bleaching. I-oxalic acid iyakwazi ukususa ngempumelelo imfucuza, imikhiqizo eminingi yokuhlanza iqukethe lesi sakhi samakhemikhali. Cishe ingxenye yesine ye-oxalic acid ekhiqizwa isetshenziselwa ukugaya izimboni nezikhumba ze-textile. Ibuye isetshenziswe njengesiguquko (i-GOST 22180-76) ku-chemistry yokuhlaziya. I-Ethanedioic acid dihydrate (i-NOOC-COOH • i-H2O) ngokusho kwe-TU 2431-002-77057039-2006 eneqhezu eliningi lomuthi oyinhloko ≥ 99.3% lisetshenziselwa izinqubo zokukhiqiza zokuhlanganiswa okuphilayo, ukuhlanzwa kusuka ekugqumeni nasekwenzeni izinsimbi, ngokugcoba kwezingxenye ezincane nge-microscopy. Abafuyi bezinyosi basebenzisa isisombululo se-oxalic acid ngengxenyana enkulu ka- 3.2% esiraphu ishukela ukuze kulawulwe i-mite ye-parasitic. Ekuqedeni kwezakhiwo ze-marble, kuqhutshwa izindawo ezizocubungula futhi zigcwale.

I-oxalic acid ne-oxalates zikhona ezitshalweni eziningi, kufaka phakathi itiye elimnyama, elitholakala ezilwaneni. Ukulimala okuyinhloko kubantu kuhlotshaniswa nokuntuleka kwengane, okuvela ekusebenzisaneni kwe-oxalic acid ne-calcium, okuholela ekungenikeni kwe- calcium oxalate eqinile (i-CaC2O4), ingxenye eyinhloko yamatshe wezinso. I-Acid iyabangela ubuhlungu emajoyini ngenxa yesikhala sezinhlanganisela ezinjalo kuzo. I-oxalic acid ingakhiwa emzimbeni ngenxa ye-metabolism ye-ethylene glycol evela emvelweni (isibonelo, i-anti-icing agent ephethe ukwelashwa kwemikhumbi kanye nezindiza ezikhungweni zezindiza, kanye neminye imithombo ye-anthropogenic). Izinkinga ezinokwenzeka nge-oxalates emzimbeni womuntu zingahlukaniswa zibe ezimbili. Okokuqala - ukwenziwa okuphawulekayo kwe-calcium kuhlotshaniswa ne-oxalic acid kanye nokuntuleka kwayo emaqenjini amathishu kanye nezitho zakhiwa. Owesibili ukwakhiwa kwamatshe aso. Inani elikhulu kakhulu le-oxalic acid litholakala esipinashi, amaqabunga neziqu ze-rhubarb, i-sorrel, i-beetroot, i-parsley, anyanisi oluhlaza.