Carboxylic acid

compound Chemical organic, ogama iimolekyuli iqela carboxyl ubuncinane enye nesakhiwo sayo (it elungelelaniswe carbonyl - iqela ezisebenzayo ze aldehydes kunye ketones, kunye hydroxyl - utywala iqela functional) lafumana igama eliqhelekileyo - carboxylic acid. Formula kubo angamelwa njengoko R-COOH, apho R i monovalent ezizizembiwa iqela esebenza. Nayiphi carboxylic acid, ngokuchaseneyo ezininzi asidi ezingaphiliyo, amandla kunye ngokupheleleyo inqanyulwe zibe ion.

Njengokuba le mizekelo elula na formic (methane) H-COOH acid. Igama ibhekisa kwimbali lokuqala zokufunyanwa kwayo ngo-1670 ezibomvu semvelo IsiNgesi John Ray. I carboxylic acid ukuba amaqela amabini okanye ngaphezulu carboxyl iya kubizwa ngokuba dibasic (dicarboxylic), tribasic (okanye tricarboxylic) njalo njalo. Umzekelo elula oxalic acid kunye C2H2O4 yayo ifomula, kwi molecule equlethe amaqela amabini carboxyl. Njengoko shestiosnovnoy kungakhokelela mellitic (geksakarbonovuyu) asidi, C12H6O12 yayo ifomula. Le molecule iqulathe amaqela carboxyl ezintandathu kutshintshwa isangqa benzene atom hydrogen.

asidi Organic ngokuqhelekileyo zifumaneka kwindalo. Umzekelo, geksakarbonovaya acid equlethwe amatye nobusi ezifumaneka lignites).

Zininzi khompawundi zendalo ezibalulekileyo kule klasi. Ezi ziquka citric acid C6H8O7 (imele ongeziweyo ukutya eziliqela E330-E333), nto leyo ifunyenwe ntlandlolo intlama yejusi yelamuni ezimuncu ngo-1784 yi ayinikiwe Swedish K. Scheele. Tartaric acid C4H6O6 i additive ukutya E334). Le asidi carboxylic zisasazwa kwindalo. Ikhoyo nokubakho incindi entsha iziqhamo ezininzi.

Ukuba liqwalasele uthotho homologous ze-oganikhi khompawundi, kuyo kukho utshintsho rhoqo zokuhlola kunye ekwandiseni ubunzima eziphilayo. Iimpawu compound nganye ixhomekeke isakhiwo ezo molekyuli, oko kukuthi, ngeendlela ezininzi ichaza isomerism asidi zabo carboxylic. Abameli zokuqala kuthotho homologous wabumba formic acid, kuquka acetic kunye propionic, libhekisela ulwelo. Bona lubonakala ivumba elitsarhayo kwaye lula enyibilikayo emanzini. Abameli eziphezulu eziqinileyo ezo musa ukuluhlakaza emanzini.

Iipropati lwemichiza asidi carboxylic ikakhulu kumiselwa impembelelo qela carbonyl i kwiqela hydroxyl. Ngoko ke, ezi zihlanganisi, ngokwahlukileyo ukuya alkoholi, abe acid uphawu ngokukhawuleza.

Ngokomzekelo, xa izisombululo zolwelo, ukuze kwahlula zibe ion, nto leyo engqina ukuba imibala ulwelo emva ngokongeza litmus ebomvu. Oku kubonisa ubukho ukuse- hydrogen. Oko kukuthi, medium kwezisombululo yabo zolwelo yi asidi (pH ngaphantsi kwe-7).

Xa kunxityelelwana isinyithi okanye iziseko ekwaziyo zokubumba iityuwa acid carboxylic: 2CH3-COOH + MG → (CH3-COO) 2Mg + H2 ↑.

asidi Organic kwakhona angene ekudibaneni kwemichiza kunye carbonates, kancinane asidi: 2CH3-COOH + MgCO3 → (CH3-COO) 2Mg + H2O + CO2 ↑.

Bona lula azithethelele ammonia ukwenza iityuwa: CH3-COOH + NH3 → CH3-COONH4.

Mihlaba emuncu luyenyuka xa asidi eziphilayo zikhona ngokugqibeleleyo kunye substituent nefuthe elibi ezenza. Umzekelo, inyathelo neklorin acetic acid ngokuthe ukubuyisela enye hydrogen atom athom chlorine nokufumana chloroacetic acid, dichloroacetic acid, uze trichloroacetic acid, kukho esibukhali ukwanda iipropati zabo asidi.

Nayiphi carboxylic acid zingafumaneka ngeendlela ezininzi. Avamise kakhulu indlela, olusekelwe phezu ukusabela igcwala. Njengoko intlawulo yokuqala reactants alkoholi okanye aldehydes. Enye indlela yokuvelisa asidi zomgquba ke haydrolisis of nitriles elibaleka ngokufudumeza ngokubanika asidi kwezimbiwa olufakwe.