Hauv kab lus no peb yuav xav txog qhov tshwm sim ntawm oxidation. Qhov no yog ntau lub tswv yim uas tshwm sim hauv ntau yam kev tshawb fawb, xws li biology thiab chemistry. Peb kuj yuav tau paub ntau yam ntawm cov txheej txheem no thiab nws cov ntsiab lus.
Introduction
Los ntawm qhov pib thiab qhov tseem ceeb ntawm qhov pom, oxidation yog txheej txheem ntawm cov tshuaj lom neeg, uas yog nrog los ntawm kev nce qib ntawm atomic oxidation ntawm cov khoom uas dhau mus. Qhov tshwm sim no tshwm sim vim kev hloov ntawm electrons los ntawm ib lub atom (reductant thiab pub) mus rau qhov thib ob (acceptor thiab oxidizer).
Lub ntsiab lus no tau qhia rau hauv kev sib tw ntawm chemistry thaum pib ntawm lub xyoo pua 19th, thiab Academician V. M. Severgin los tsim ib qho kev taw qhia qhia txog kev sib cuam tshuam ntawm cov tshuaj nrog oxygen los ntawm huab cua.
Qee zaum, oxidation ntawm ib lub molecule yog nrog los ntawm kev tsim ntawm instability nyob rau hauv cov qauv ntawm cov khoom thiab ua rau nws lwj mus rau hauv molecules nrog ntau dua stability thiab me me. Qhov tseeb yog tias cov txheej txheem no tuaj yeem rov ua dua ntawm ntau qib sib txawv. Ntawd yog, me me particle tsim tuaj yeem ua taumuaj qib oxidation ntau dua li cov atomic particles uas yog thawj hauv tib yam khoom, tab sis loj thiab ruaj khov.
Nyob rau hauv chemistry muaj lub tswvyim ntawm qhov qis tshaj thiab siab tshaj plaws ntawm oxidation. Qhov no tso cai rau peb faib cov atom raws li lawv lub peev xwm los nthuav tawm cov khoom no. Qhov siab tshaj plaws oxidation xeev sib haum mus rau tus naj npawb ntawm cov pab pawg neeg nyob rau hauv lub caij. Qhov qis tshaj plaws, raws li txoj cai, yog txiav txim los ntawm kev sib txuas lus ntawm tus lej thiab tus lej khib: siab tshaj 8=qis tshaj 2, siab tshaj 7=qis tshaj 1.
Combustion
Combustion yog txheej txheem oxidation. Hauv huab cua atmospheric (nrog rau hauv ib puag ncig ntawm cov pa ntshiab) lawv tuaj yeem oxidized nyob rau hauv daim ntawv ntawm combustion. Ntau yam khoom siv tuaj yeem ua piv txwv: cov ntsiab lus yooj yim tshaj plaws ntawm cov khoom ntawm cov hlau thiab cov hlau tsis muaj hlau, inorganic thiab organic compounds. Txawm li cas los xij, qhov tseem ceeb tshaj plaws yog cov khoom siv hluav taws xob hluav taws xob (roj), cov uas yog cov khoom qub ntawm cov roj, gases, thee, peat, thiab lwm yam. Feem ntau lawv tsim los ntawm kev sib xyaw ua ke ntawm hydrocarbons nrog ib feem me me ntawm oxygen, sulfur, nitrogen-muaj cov organic tebchaw, nrog rau cov kab sib txuas ntawm lwm cov khoom.
Biological oxidation
Nyob rau hauv biology, oxidation cov tshuaj tiv thaiv yog cov txheej txheem uas ua ke rau kev hloov pauv hauv lub xeev oxidation ntawm cov atoms koom nrog cov tshuaj tiv thaiv, thiab qhov no tshwm sim vim kev faib hluav taws xob ntawm cov khoom sib cuam tshuam.
Thawj qhov kev xav yog tias hauv txhua yam kab mob nyob hauv cov tshuaj lom neeg tshaj plaws. cov tshuaj tiv thaiv, tau muab tso rau hauv lub kaum yimxyoo pua. Fabkis chemist A. Lavoisier tau kawm txog qhov teeb meem. Nws tau mob siab rau qhov tseeb tias cov chav kawm ntawm combustion thiab oxidation hauv biology zoo ib yam li ib leeg.
Cov kws tshawb fawb tau tshawb fawb txog txoj hauv kev ntawm cov pa oxygen uas tau nqus los ntawm cov neeg muaj sia vim ua pa. Lawv tau tshaj tawm tias cov txheej txheem oxidation no yog cov txheej txheem zoo sib xws uas tshwm sim ntawm tus nqi sib txawv. Nws tau mob siab rau cov txheej txheem decomposition, uas, raws li nws tau muab tawm, yog raws li qhov tshwm sim ntawm kev sib cuam tshuam ntawm cov pa molecule (oxidizing tus neeg sawv cev) nrog cov khoom siv organic uas suav nrog carbon thiab / lossis hydrogen atoms. Raws li qhov tshwm sim ntawm decomposition, kev hloov pauv ntawm cov teeb meem tshwm sim.
Muaj lub sijhawm ntawm cov txheej txheem uas cov kws tshawb fawb tsis tuaj yeem nkag siab tag nrho, suav nrog cov lus nug:
- Vim yog vim li cas oxidation tau ua nyob rau hauv cov xwm txheej ntawm lub cev kub, txawm tias nws nyob sab nraum lub cev, tsuas yog kub.
- Vim yog vim li cas, cov tshuaj tiv thaiv oxidation yog qhov tshwm sim uas tsis yog nrog los ntawm kev tso tawm cov nplaim taws, nrog rau kev tso tawm ntau lub zog.
- "kev kub hnyiab" ntawm cov khoom siv hauv lub cev yog li cas, yog tias nws yog 80% (kwv yees) muaj kua - dej H2O.
Hom kab mob oxidation
Raws li cov xwm txheej ntawm ib puag ncig uas oxidation tshwm sim, nws muab faib ua ob hom. Feem ntau cov kab mob fungi thiab microorganisms tau txais cov khoom siv hluav taws xob los ntawm kev hloov cov as-ham los ntawm cov txheej txheem anaerobic. Qhov no tshwm simtshwm sim yam tsis tau nkag mus rau molecular oxygen, thiab tseem hu ua glycolysis.
Ib txoj hauv kev nyuaj dua ntawm kev hloov cov khoom noj khoom haus yog aerobic daim ntawv ntawm cov roj ntsha oxidation lossis cov ntaub so ntswg ua pa. Qhov tsis muaj oxygen ua rau cov hlwb tsis tuaj yeem oxidize rau lub zog thiab lawv tuag.
Tau lub zog los ntawm lub cev muaj sia
Nyob hauv biology, oxidation yog ib qho tshwm sim ntau yam:
- Glycolysis yog thawj theem ntawm cov kab mob heterotrophic, thaum lub sijhawm cov monosaccharides yog cleaved yam tsis muaj oxygen, thiab nws ua ntej pib cov txheej txheem ntawm kev ua pa ntawm tes.
- Cov txheej txheem ntawm decomposition ntawm beta-fatty acids yog ib qho tshwm sim ua ke nrog oxidation ntawm pyruvate, lub hom phiaj ntawm kev ua ntawm txhua fatty acid rau hauv acetylcoenzyme. Tsis tas li ntawd, cov tshuaj no tau muab rau lub voj voog tricarboxylic acid.
- Krebs cycle - hloov pauv ntawm acetylcoenzyme rau hauv citric acids thiab ntxiv rau kev hloov pauv tom ntej (phenomena ntawm dehydrogenation, decarboxylation thiab rov tsim dua tshiab).
- Oxidative phosphorylation yog kauj ruam kawg ntawm kev hloov pauv uas cov kab mob eukaryotic hloov pauv adenosine diphosphate rau adenosine triphosphoric acids.
Y Pyruvate oxidation - hloov pauv ntawm pyruvic acids rau hauv acetylcoenzyme. Cov tshuaj tiv thaiv no tsuas yog ua tau nrog kev koom tes ntawm pyruvate dehydrogenase enzyme complexes.
Nws ua raws li oxidation yog txheej txheem uas muaj:
- phenomenontshem tawm hydrogen los ntawm substrate, uas dhau oxidation (dehydrogenation);
- substrate electron recoil phenomenon;
- qhov tshwm sim ntawm qhov sib ntxiv ntawm cov pa oxygen molecule rau lub substrate.
Reaction tshaj hlau
Oxidation ntawm cov hlau yog cov tshuaj tiv thaiv thaum lub sijhawm, los ntawm kev sib cuam tshuam ntawm cov khoom los ntawm pawg hlau thiab O2, oxides (oxides) raug tsim.
Hauv kev txiav txim siab dav dav, cov tshuaj tiv thaiv uas lub atom poob ib qho hluav taws xob thiab tsim ntau yam sib txuas, piv txwv li, cov tshuaj chlorides, sulfides, thiab lwm yam. xeev (nyob rau hauv daim ntawv ntawm ore). Nws yog vim li no tias cov txheej txheem oxidation tau nthuav tawm raws li kev txo cov tshuaj tiv thaiv ntawm ntau yam ntawm cov khoom sib xyaw. Xyaum siv cov khoom ntawm cov hlau thiab lawv cov alloys, thaum cuam tshuam nrog ib puag ncig, maj mam oxidize - lawv raug corrosion. Cov txheej txheem hlau oxidation tshwm sim vim yog cov thermodynamic thiab kinetic yam.
Valence thiab oxidation
Lub xeev oxidation yog qhov muaj nuj nqis. Txawm li cas los xij, muaj qee qhov sib txawv ntawm lawv. Qhov tseeb yog qhov valency ntawm chem. element txiv neej txiav txim siab lub peev xwm ntawm ib lub atom los tsim ib tug xov tooj ntawm cov tshuaj bonds nrog rau lwm yam atoms. Qhov no yog vim muaj ntau hom atom, feem, sib txawv muaj peev xwm los tsim kev sib raug zoo. Txawm li cas los xij, valence tuaj yeem tsuas yog nyob rau hauv covalent compound thiab yog tsim los ntawm kev tsim cov khoom siv hluav taws xob sib txawv ntawm cov atoms. Qiboxidation, nyob rau hauv sib piv rau valency, yog lub degree ntawm conditional nqi uas ib tug atom ntawm ib yam khoom muaj. Nws tuaj yeem yog qhov zoo "+", xoom "0" thiab tsis zoo "-". Tsis tas li ntawd, lub xeev oxidation qhia tias txhua daim ntawv cog lus hauv cov khoom yog ionic.
Reaction hla dej
Ntau tshaj li ob txhiab xyoo dhau los, cov kab mob cog tau coj ib qho ntawm cov kauj ruam tseem ceeb tshaj plaws rau qhov pib ntawm evolution. Cov txheej txheem ntawm photosynthesis pib ua cov duab. Txawm li cas los xij, thawj zaug tsuas yog txo cov tshuaj ntawm hom hydrogen sulfide tau raug photooxidation, uas muaj nyob hauv ntiaj teb hauv qhov me me heev. Dej oxidation yog ib txheej txheem uas qhia txog qhov tseem ceeb ntawm molecular oxygen rau hauv qhov chaw. Qhov no tso cai rau cov txheej txheem bioenergetic txav mus rau qib aerobic tshiab. Tib qhov tshwm sim tau tso cai tsim cov ntaub thaiv npog ozone uas tiv thaiv lub neej hauv ntiaj teb.
