Carboxylic acid

Chemical kwayoyin fili, wanda kwayoyin da a kalla daya carboxyl kungiyar a tsarinta (da shi masu hada carbonyl - aikin kungiyar na aldehydes da ketones, kuma hydroxyl - barasa aikin kungiyar) samu kowa sunan - carboxylic acid. Formula su za a iya wakilta a matsayin R-COOH, inda R ne monovalent hydrocarbon aikin kungiyar. Duk wani carboxylic acid, da bambanci ga mafi inorganic acid, rauni, kuma incompletely barranta zuwa ions.

Kamar yadda mafi sauki misalai ne formic (methane) H-COOH acid. Sunan nufin da tarihi na farko na ta samu a 1670 na ja tururuwa English halittu John Ray. A carboxylic acid da ciwon biyu ko fiye carboxyl kungiyoyin za a kira dibasic (dicarboxylic), tribasic (ko tricarboxylic) da sauransu. A sauki misali ne oxalic acid da kuma ta dabara C2H2O4, a cikin kwayoyin da ya ƙunshi biyu carboxyl kungiyoyin. Kamar yadda shestiosnovnoy iya kai mellitic (geksakarbonovuyu) acid, ta dabara C12H6O12. Jigidar halittar ƙunshi shida carboxyl kungiyoyin an maye gurbinsu a benzene zobe hydrogen atoms.

Organic acid yawanci samu a yanayi. Alal misali, geksakarbonovaya acid kunshe ne a cikin zuma duwatsu samu a lignites).

Akwai da yawa muhimmanci na halitta da mahadi a cikin wannan aji. Wadannan sun hada da citric acid C6H8O7 (wakiltar dama abinci Additives E330-E333), wanda aka asali samu daga unripe lemun tsami ruwan 'ya'yan itace a cikin 1784 da Swedish harhaɗa magunguna K. Scheele. Tartaric acid C4H6O6 ne a abinci ƙari E334). Wannan carboxylic acid da aka rarraba shi ko'ina a yanayi. An dauke a cikin sabo ne ruwan 'ya'yan itace na da yawa' ya'yan itãcen marmari.

Idan muka yi la'akari da wani homologue jerin hanyoyin gudanar da mahadi, a cikinsa akwai yau da kullum da canje-canje a cikin kaddarorin da kara kwayoyin nauyi. A Properties na kowane fili ya dogara ne a kan tsarin da kwayoyin, wato, a mutunta mutane da yawa ma'anar su isomerism carboxylic acid. A farko wakilan da homologue jerin kafa daga formic acid, ciki har da acetic da propionic, tana nufin wani ruwa. Suna halin a pungent wari da kuma masu readily mai narkewa a cikin ruwa. A mafi girma wakilan ne daskararru wanda ba narke a cikin ruwa.

Chemical Properties na carboxylic acid yafi ƙaddara da tasiri na carbonyl kungiyar zuwa hydroxyl kungiyar. Saboda haka, wadannan mahadi, da bambanci ga alcohols, da pronounced acid hali.

Alal misali, a cikin ruwa-ruwa mafita, da suka iya dissociate cikin ions, wanda ya tabbatar da cewa ruwa canza launi bayan da ƙara litmus ja. Wannan ya nuna gaban hydrogen cations. Ina nufin mai ruwa-ruwa mafita na yanayi ne acidic (PH kasa da 7).

Lokacin da hulda da karafa ko sansanonin iya kafa carboxylic acid salts: 2CH3-COOH + MG → (CH3-COO) 2Mg + H2 ↑.

Organic acid ma shiga cikin sinadaran halayen da carbonates, wuce carbonic acid: 2CH3-COOH + MgCO3 → (CH3-COO) 2Mg + H2O + CO2 ↑.

Su readily amsa tare da ammonia ta samar da salts: CH3-COOH + NH3 → CH3-COONH4.

A acidic Properties an inganta a lokacin da Organic acid ne ba a cikin m da wani substituent korau inductive sakamako. Alal misali, mataki na chlorine a acetic acid aka hankali ya maye gurbin daya hydrogen zarra na chlorine kwayoyin zarra da samun chloroacetic acid, dichloroacetic acid, sa'an nan trichloroacetic acid, akwai wani kaifi karuwa a cikin acidic Properties.

Duk wani carboxylic acid za a iya samu a hanyoyi da dama. Mafi na kowa ne hanya, wanda ta dogara ne a kan dauki na hadawan abu da iskar shaka. Kamar yadda da farko lura da reactants alcohols ko aldehydes. Wani Hanyar samar da Organic acid ne hydrolysis na nitriles gudãna ta gasa su da diluted ma'adinai acid.