Carboxylic acid

Makemikari emakemikari anokwana, ayo ma molecule ane boka rimwe chete re carboxyl (carbonyl-functional group of aldehydes uye ketone pamwe chete , uyewo hydroxyl-functional group of alcohols) muchimiro chakawana zita rakafanana - carboxylic acid. Shanduro yavo inogona kuenzanisirwa saR-COOH, uko R iri boka re hydrocarbon monovalent functional group. Chero carboxylic asidi, kusiyana nemafuta akawanda easidganic, isina simba uye haikwanisi kuparadzaniswa kuva ions.

Mienzaniso yakajeka ndeye formic acid (methane) H-COOH. Zita racho rinotsanangurwa nenhoroondo yerisitiro yayo yokutanga muna 1670 yezvitsvuku zvakatsvuka neAngland mutori wenhau John Ray. Carboxylic acid nemapoka maviri kana kupfuura e-carboxyl achanzi dibasic (kana dicarboxylic), tribasic (kana tricarboxylic), nezvimwe zvakadaro. Muenzaniso wakareruka ndeye oxalic acid pamwe nemhando yayo C2H2O4, mu molecule iyo mune mapoka maviri e carboxyl. Senguva ye hexafluoric acid, zvinokwanisika kupa mellitic (hexacarboxylic) asidi, chimiro C12H6O12. Iko molecule ine mapoka matanhatu e carboxyl, ayo akatsiva maatomu ehydrojeni mubheji reBenzene.

Organic acids, sekutonga, inowanikwa mune zvakasikwa. Semuenzaniso, hexacarboxylic acid inowanikwa mubwe reuchi rinowanikwa mumarasha akaoma).

Iko kune zvakawanda zvakakosha masikirwo edziklasi ino. Izvi zvinosanganisira citric acid C6H8O7 (zvishomanana zvezvokudya E330-E333), izvo zvakatanga kuwanikwa kubva mujusi wemamori asina kuibva muna 1784 neSweden wemasimusi K. Scheele. Tartaric acid C4H6O6 zvokudya zvinowedzera E334). Iyi carboxylic acid inoparadzirwa zvikuru mumasikirwo. Inowanikwa mujusi mutsva yezvibereko zvizhinji.

Kana tikatarisa mhando ipi neipi yekubatana kwezvinhu izvi zvinokonzerwa nemiti, saka pane kuchinja nguva dzose muimba nekuwedzera kwema molecular weight. Izvo zvikamu zvechikamu chimwe nechimwe zvinoenderana nesarudzo yemamoreksi awo, ndiko kuti, ayo anonyanya kugadziriswa nehutongi hwe carboxylic acid. Mumiririri wekutanga wei homologous series yakagadzirwa kubva ku formic acid, kusanganisira acetic uye propionic, zvinoreva zvinodhaka. Zvinonhuwira zvakanyanya uye zvinononoka kusanganiswa mumvura. Vamiriririri vepamusoro mashoma, asingasviki mumvura.

Icho chemikemikari ye carboxylic acids inonyanya kutsanangurwa nemigumisiro yeboka re carbonyl pane boka re hydroxyl. Saka, izvi zvinokonzerwa, zvakasiyana nedorosi, zvine chirevo chechidimbu chechimiro.

Semuenzaniso, mune mhinduro dzakawanda, dzinogona kuparadzanisa kuva ions, izvo zvinoratidza kudonha kwemvura pashure pokuwedzera litmus kuti iite tsvuku. Izvi zvinoratidza kuvapo kwehydrogen cations. Ichocho, iyo inoshandiswa pakutsvaga kwayo inopisa yakaoma (pH pasi pe7).

Kana uchitaurirana nesimbi kana zvigadziko, carboxylic acids inokwanisa kugadzira masaiti: 2CH3-COOH + Mg → (CH3-COO) 2Mg + H2 ↑.

Organic acids inopinda mumakemikari ekugadzirisa ne carbonates, ichibudisa carbonic acid: 2CH3-COOH + MgCO3 → (CH3-COO) 2Mg + H2O + CO2 ↑.

Vanoita nyore nyore neammonia, vachiumba salits: CH3-COOH + NH3 → CH3-COONH4.

Acidic properties ye organic acids inosimbiswa nekuvapo kwemasimba makuru mukati mavo nehuwandu hwekudzivirira. Somuenzaniso, pasi pekushandiswa kweklorini pane acid acidtic, zvishoma nezvishoma kushandisa atomu imwe yehydrogen nemaatomu eklorini uye kuwana chloroacetic asidi, ipapo dichloroacetic acid uye trichloroacetic acid, pane kuwedzera kwakanyanya kwezvinhu zvakasimba mukati mavo.

Chero carboxylic acid inogona kuwanikwa munzira dzakawanda. Nzira yakakurumbira inowanikwa pahutachiona hunoita. Sezvokutanga reagents, alcohols kana aldehydes zvinotorwa. Imwe nzira yekubudisa biori acid ndiyo hydrolysis ye nitriles, iyo inowanikwa apo inopisa nekuderedza mineral acids.