El i-formic acid o I-Methanoic acid iyinhlanganisela elula nencane kakhulu yawo wonke ama-asidi aphilayo. Inefomula ye-molecular HCOOH ene-athomu ye-hydrogen eyodwa kuphela ehlanganiswe ne-athomu yekhabhoni. Igama layo livela egameni elithi formica, elisho intuthwane ngesiLatini. Kuyinhlanganisela ebaluleke kakhulu emhlabeni we-chemistry futhi isetshenziswa kabanzi namuhla.
Ngenxa yalesi sizathu, sizonikezela lesi sihloko ukukutshela konke okudingeka ukwazi mayelana ne-formic acid, izici zayo nokubaluleka kwayo.
Izici eziyinhloko
Izazi zemvelo zekhulu leshumi nanhlanu zathola ukuthi izinhlobo ezithile zezinambuzane (ama-termicides), njenge izintuthwane, umuhlwa, izinyosi namabhungane, bakhipha lenkomponi eyenza ukulunywa kwabo kube buhlungu. Ngaphezu kwalokho, lezi zinambuzane zisebenzisa le nhlanganisela njengendlela yokuhlasela, ukuzivikela kanye nokubonisa amakhemikhali.
Zinezindlala ezinobuthi ezikhipha lokhu kanye namanye ama-asidi, njenge-acetic acid, emzimbeni ngendlela yenkungu. I-Formic acid inamandla kune-acetic acid (CH3COOH); ngakho-ke, inani elilinganayo le-formic acid elincibilikisiwe emanzini lizoholela esixazululweni esine-pH ephansi.
Isazi semvelo esiyiNgisi uJohn Ray wafinyelela ukuhlukaniswa kwalesi sakhiwo ngo-1671, ekhishwe enanini elikhulu lezintuthwane. Ngakolunye uhlangothi, ukuhlanganiswa kokuqala okuphumelelayo kwalesi sakhiwo kwenziwa isazi samakhemikhali saseFrance kanye nesazi sefiziksi uJoseph Gay-Lussac esebenzisa i-hydrocyanic acid (HCN) njenge-reagent.
i-formic acid emvelweni
I-formic acid ingaba khona emazingeni asemhlabeni, njengengxenye ye-biomass noma emkhathini, ibamba iqhaza ezinhlobonhlobo zokusabela kwamakhemikhali, ingatholakala ngisho nangaphansi komhlaba, emafutheni noma esigabeni segesi ebusweni bayo.
Mayelana ne-biomass, izinambuzane nezitshalo zingabakhiqizi abakhulu bale asidi. Lapho izinto zokubasa ezimbiwa phansi zivutha, zikhiqiza i-gaseous formic acid; ngakho-ke, izinjini zezimoto zikhulula le asidi emkhathini.
Nokho, ziningi izintuthwane ezihlala emhlabeni, futhi ukukhiqizwa kwe-formic acid phakathi kwabo kukhulu ngokuphindwe izikhathi eziyizinkulungwane kune-methanoic acid ekhiqizwa imboni yabantu ngonyaka owodwa. Imililo yamahlathi nayo iwumthombo we-fomic acid.
Phezulu phezulu, ku-matrix yomoya oyinkimbinkimbi, izinqubo ze-photochemical zokuhlanganiswa kwe-formic acid zenzeka. Kuleli qophelo, ama-volatile organic compounds (VOCs) awonakala ngaphansi kwesenzo semisebe ye-UV noma afakwe i-oxid nge-OH radical mechanism. I-chemistry yomoya ecebile futhi eyinkimbinkimbi ikude kakhulu umthombo oyinhloko we-methanoic acid emhlabeni.
Isakhiwo se-athomu se-formic acid
Umfanekiso ongenhla ubonisa ukwakheka kwe-gas phase dimer ye-formic acid. Ama-athomu amhlophe ahambisana nama-athomu e-hydrogen, abomvu ama-athomu omoya-mpilo kanye nama-athomu e-carbon.
Amaqembu amabili angabonakala kulawa ma-molecule: i-hydroxyl (-OH) ne-formyl (-CH=O), ezikwazi ukwenza izibopho ze-hydrogen. Lokhu kusebenzisana kuwuhlobo lwe-OHO, lapho iqembu le-hydroxyl lingumnikezeli we-H futhi iqembu le-formyl lingumnikezeli we-O.
Kodwa-ke, i-H eboshwe kuma-athomu ekhabhoni ayinalo leli khono. Lokhu kusebenzisana kunamandla kakhulu, futhi i-hydrogen eseqenjini le-OH ine-asidi eyengeziwe ngenxa ye-athomu ye-H entula i-electron; Ngakho, le hydrogen iqhubeka nokuzinza ibhuloho. Njengomphumela walokhu okungenhla, i-formic acid ikhona njenge-dimer hhayi njenge-molecule ngayinye.
Njengoba izinga lokushisa lehla, i-dimer iqondisa amabhondi ayo e-hydrogen ukuze idale isakhiwo esizinzile namanye ama-dimers, okuholela kumaketanga e-alpha nawe-beta angapheli e-methanoic acid. Lesi sakhiwo sekristalu Kuncike ezintweni eziguquguqukayo ezibonakalayo ezisebenza kukho, njengokucindezela kanye nezinga lokushisa.. Ngakho-ke, intambo iyaguquleka. Uma ukucindezela kwenyuka kuya emazingeni adlulele, amaketanga acindezelwa ngokwanele ukuze athathwe njenge-crystalline polymer ye-formic acid.
Ama-propiedades
Sizogxila ekuchazeni izakhiwo eziyinhloko ze-formic acid:
- i-methanoic acid uketshezi olungenambala ekamelweni lokushisa elinephunga elimnandi elinamandla. Inesisindo semolekyuli esingu-46g/mol, indawo yokuncibilika engu-8,4ºC kanye nephuzu lokubilisa elingu-100,8ºC, ngaphezu kwamanzi.
- Ixubene namanzi nezincibilikisi zemvelo ezishisayo njenge-ether, i-acetone, i-methanol ne-ethanol.
- Kunalokho, kuzincibilikisi ezinephunga elimnandi njenge-benzene ne-toluene, ayincibiliki kahle ngoba i-formic acid inama-athomu ekhabhoni ambalwa esakhiweni sayo.
- Ine-pKa engu-3,77, okuyi-acidic kakhulu kune-acetic acid, engachazwa ngoba iqembu le-methyl lihlinzeka ngokuminyana kwe-electron ku-athomu ye-carbon oxidized ngama-oxygen amabili. Lokhu kubangela ukwehla kancane kwe-asidi yamaproton (CH3COOH, HCOOH).
- Lapho i-asidi isusiwe, iguqulelwa ku-formate anion HCOO-, esusa ukushajwa okunegethivu phakathi kwama-athomu amabili omoya-mpilo. Ngakho-ke, i-anion ezinzile futhi inesibopho se-asidi ephezulu ye-formic acid.
Ukusetshenziswa kwe-Formic Acid
Imboni yokudla nezolimo
Iyingozi njenge-methanoic acid, isetshenziswa ekugxiliseni okwanele njengendlela yokulondoloza ukudla ngenxa yomphumela wayo we-antibacterial. Ngesizathu esifanayo sokuthi isetshenziswa kwezolimo, ibuye ibe nezindawo zokubulala izinambuzane. Iphinde ibe nomthelela obulalayo otshanini futhi isiza ukuvimbela igesi yamathumbu ezilwaneni zasemapulazini.
Imboni yezindwangu nezicathulo
Isetshenziswa embonini yendwangu ukudaya nokucwenga izindwangu futhi cishe iyona ndlela esetshenziswa kakhulu le acid. I-asidi ye-Formic isetshenziselwa ukucutshungulwa kwesikhumba kanye nokuchithwa kwalolu lwazi nge isenzo sayo sokwehlisa amafutha. Ukuncishiswa kwe-formic acid kuguqulela ku-anion e-formate HCOO-, esusa ukushajwa okunegethivu phakathi kwama-athomu amabili omoya-mpilo. Ngakho-ke, i-anion ezinzile futhi inesibopho se-asidi ephezulu ye-formic acid.
Ukuphepha emgwaqeni
Ngokungeziwe ekusetshenzisweni kwezimboni okucacisiwe, okuphuma ku-formic acid (ifomethi) kusetshenziswa emigwaqweni yasebusika e-Switzerland nase-Austria. ukunciphisa ingozi yezingozi. Lokhu kwelashwa kuphumelela kakhulu kunokusebenzisa usawoti wetafula.
Ngithemba ukuthi ngalolu lwazi ungafunda kabanzi mayelana ne-formic acid, ukwakheka kwayo nokusetshenziswa kwayo.