Acetic acid

Noma organic monobasic carboxylic acid, i-molecule ye equkethe athomu amabili-carbon futhi iqembu carboxyl (lethiwa ngoba siqukethe carbonyl futhi carboxyl amaqembu), ngokuthi ethane (by Isifaniso ne alkane netinombolo zama-athomu carbon) noma acetic acid. Yena, njengabo bonke amalungu aphansi aliphatic alesi sigaba of organic compounds, has a iphunga okunoshukela. Its chemical ifomula singatlolwa bunjesi: CH3COOH. Ngezinye izimo kuma uketshezi kungekho nto enemibala emihle. Ubuningi - 1.05 g / cm³. mass izinyo lomhlathi ilingana 60,05 g / Mol. Lincibilike ezingeni lokushisa 16,75 ° C (ngezansi zinhlayiya eqina efana ice, abizwa kanjalo ice). Amathumba ezingeni lokushisa 118,1 ° C. Inkomba yezokubona ilingana 1.372.

Abamele lesi sigaba of organic compounds kuyinto ntekenteke acid hydrochloric noma sulfuric, kodwa uma iqhathaniswa carbonic acid, ahlaselwe kabi ubhadane lwesifo kuyinto acetic acid. I nezakhi ezithile zamakhemikhali kunqunywa amalungu ayo yezinhlayiya carbonyl namaqembu hydroxyl. Bona kungayithonya kakhulu ngakho komunye nomunye ukuthi izakhiwo amakhemikhali impahla kuphela ngezinga elincane okusikhumbuza izakhiwo carbonyl compounds (aldehydes, amides, ketones, esters) noma alcohols. Ionization kwenzeka O-H ukuxhumana ngenxa edonsa electron carbonyl iqembu. Ngakho-ke, ukuxhumana okulula kakhulu ukulinakekela Nqamula kuka e alcohols. I displacement electron kusukela iqembu hydroxyl a carbonyl kancane kunciphisa carbon athomu icala omuhle, okwenza kube nzima ukuhlasela ngayo nucleophile. Ngakho-ke, izinto eziningi uxhumana kalula carbonyl compounds ungathathi ngamawala nge CH3COOH.

Ngokwezinga elithileko encane acetic acid kungaba Nqamula ukwakha hydrogen ion: CH3COOH + H2O ↔ CH3CO2ˉ + H3O +. It libhekene neutralization lezisekelo, okwaphumela usawoti kumiswa: NaOH + CH3COOH → CH3COONa + H2O . Carboxylic acid nosawoti ngokuvamile amanzi encibilikayo. Lesi sici kusiza isizinda kusuka imithombo yemvelo. Ngakho-ke acid babephakathi kwabokuqala behlukene le izinto eziphilayo. Ngokwesibonelo, ethane etholwe iwayini elimuncu. Namandla hydrogen izibopho akhiwa phakathi molecule CH3COOH, ngaleyo ndlela ezihogelwayo futhi esigabeni igesi, ke ikhona njengenkampani dimer.

Acetic acid namanzi kumane nje kuyizinto miscible zonke ngezabelo. It sishintsha impahla yayo kuncike okuhlushwa. Ngokulingene nolaka maqondana izinsimbi, kuhlanganise yensimbi, magnesium ne-zinc. Lokhu kuveza hydrogen ne usawoti okuthiwa acetates: MG + 2 CH3COOH → (CH3COO) 2Mg + H2 ↑. Njengoba aluminium lwakha acid nemithi passivation ifilimu aluminiyamu oxide, ithangi aluminium, kanye engagqwali amathangi steel isetshenziselwa ukuthutha CH3COOH.

Ngo umkhakha, acetic acid kuveza namachibi i aldehyde kwegama elifanayo: 2CH3COH + O2 → 2CH3COOH. Kusukela 800 kg aldehyde okulungiselelwe ton CH3COOH. Kodwa indlela amuva ngokukhiqiza - uketshezi isigaba namachibi ka-butane ne air-mpilo ezingeni lokushisa 150-170 ° C ukucindezela eziphindwe 50: CH3CH2CH2CH3 + 2O2 → 2CH3COOH + 2 H2O. Eqinisweni, le ndlela yokusabela eliyinkimbinkimbi kakhulu kunalelo kuboniswe. Ngaphandle acetic acid, zazikhiqiza izinhlobo eziningi zala byproducts. Zombili lezi izindlela zinganakiwe (ngenxa amanani kawoyela ngaphezulu) yi-carbonylation ka methanol: CO + CH3OH → CH3COOH. Ukuqhutshwa inqubo ebukhoneni kulethe okuyinto usawoti steel, futhi abagqugquzeli (activators) - ion iodide. Ikhono kwezinye nezilwanyana ezincane kuthiwa isibilile ETHYL utshwala, kulandele namachibi e CH3COOH, kusetshenziswa ekukhiqizeni kwamakhemikhali: C2H5OH + O2 → CH3COOH + H2O . Inqubo iyinkimbinkimbi futhi senzeka ngezigaba eziningana.

Acetic acid ekhiqizwa ngokuhambisana GOST 19814-74 (zokwenziwa kutsha) GOST 18270-72 (ubumsulwa okusezingeni eliphezulu) kanye GOST 61-75 (esisheshayo). Lena kubaluleke chemical reagent namakhemikhali ezimboni ukuthi ngokuyinhloko asetshenziswa ekukhiqizeni, isetshenziselwa zepulasitiki, nezindwangu zokwenziwa, udayi, ifilimu nabanye. Kuyinto impahla eluhlaza ukwenziwa vinyl acetate esisetshenziselwa enqubeni yokukhipha sevilene (njengoba ethylene comonomer). Ukusetshenziswa acetic acid ngenxa impahla yayo zamakhemikhali ngokomzimba. CH3COOH nosawoti kukhona mordants ukuthi ukukhonza zokuthola udayi phezu fibre.

Emikhayeni ngokuvamile lwenkomo olufakwe amanzi acetic acid isetshenziswa njenge-ejenti descaling. Esikhathini umkhakha ukudla isetshenziswa ngaphansi ikhodi E260 ukudla izithasiselo ezifana asidi nomthetholawulo njengoba condiment. Ukudla okufakiwe evunyiwe ukusetshenziswa e-EU, US, Australia naseNew Zealand. Esikhathini umkhakha ukudla isetshenziswa imikhiqizo pickling ngesimo uviniga nge lokuhlushwa CH3COOH emanzini 3 kuya ku-15% noma uviniga nge ingxenyenamba mass we ketshezi eziyisisekelo 70%. Eziningana esters ka acetic acid esetshenziswa embonini confectionery.