Cov tshuaj tiv thaiv decomposition ua lub luag haujlwm loj hauv lub neej ntawm lub ntiaj teb. Tom qab tag nrho, lawv pab txhawb kev puas tsuaj ntawm cov khoom pov tseg ntawm tag nrho cov kab mob lom. Tsis tas li ntawd, cov txheej txheem no pab tib neeg lub cev kom nqus tau ntau yam sib xyaw ua ke hauv ib hnub los ntawm kev rhuav tshem lawv mus rau hauv cov yooj yim (catabolism). Ntxiv nrog rau tag nrho cov saum toj no, cov tshuaj tiv thaiv no txhawb kev tsim cov organic thiab inorganic yooj yim los ntawm cov complex. Cia peb kawm ntxiv txog cov txheej txheem no, thiab saib cov piv txwv ntawm cov tshuaj tiv thaiv decomposition.
Yuav ua li cas thiaj li hu ua tshuaj tiv thaiv hauv chemistry, hom ntawm lawv yog dab tsi thiab lawv nyob ntawm dab tsi
Ua ntej kawm txog kev decomposition, nws tsim nyog kawm txog cov txheej txheem tshuaj feem ntau. Lub npe no hais txog lub peev xwm ntawm cov molecules ntawm qee yam tshuaj los cuam tshuam nrog lwm tus thiab tsim cov tebchaw tshiab hauv txoj kev no.
Piv txwv li, yog ntawm lawv tus kheejoxygen thiab ob lub hydrogen molecules cuam tshuam, ua rau ob lub molecules ntawm hydrogen oxide, uas peb txhua tus paub tias yog dej. Cov txheej txheem no tuaj yeem sau tau siv cov khoom sib npaug hauv qab no: O.
Txawm hais tias muaj cov txheej txheem sib txawv los ntawm cov tshuaj tiv thaiv kab mob sib txawv (cov nyhuv thermal, catalysts, muaj / tsis muaj theem ciam teb, kev hloov pauv hauv oxidation xeev ntawm reactants, thim rov qab / irreversibility), lawv feem ntau faib raws li cov hom kev hloov pauv ntawm cov khoom sib cuam tshuam.
Yog li, muaj plaub yam txheej txheem tshuaj.
- Kev sib txuas.
- Txhob Cia Siab.
- Exchange.
- Nyob.
Txhua qhov kev tawm tsam saum toj no yog sau ua duab siv qhov sib npaug. Lawv lub tswv yim dav dav zoo li no: A → B.
Ntawm sab laug ntawm cov qauv no yog thawj zaug reagents, thiab sab xis yog cov khoom tsim los ntawm cov tshuaj tiv thaiv. Raws li txoj cai, nws yuav tsum raug kub hnyiab, hluav taws xob, lossis siv cov khoom siv catalytic los pib nws. Lawv lub xub ntiag yuav tsum tau qhia nyob rau hauv kev sib npaug tshuaj.
Dab tsi yog qhov kev tawm tsam decomposition (splitting)
Cov txheej txheem tshuaj lom neeg no yog tsim los ntawm kev tsim ntawm ob lossis ntau lub tebchaw tshiab los ntawm cov molecules ntawm ib yam khoom.
Hauv cov ntsiab lus yooj yim, cov tshuaj tiv thaiv ntawm decomposition tuaj yeem muab piv rau lub tsev los ntawm tus tsim qauv. Tom qab txiav txim siab los tsim ib lub tsheb thiab lub nkoj, tus me nyuam disassembles tus qauv pib thiab tsim ib qho uas xav tau los ntawm nws qhov chaw. Nyob rau tib lub sijhawm, cov qauv ntawm cov ntsiab lus lawv tus kheejtus constructor tsis hloov, ib yam li nws tshwm sim nrog cov atoms ntawm cov tshuaj koom nyob rau hauv lub splitting.
qhov sib npaug ntawm qhov kev txiav txim siab zoo li cas
Txawm hais tias muaj ntau pua lub tebchaw muaj peev xwm sib cais cov tshuaj complex rau hauv cov khoom siv yooj yim, tag nrho cov txheej txheem no tshwm sim raws li tib txoj cai. Koj tuaj yeem piav qhia nws siv cov qauv schematic: ABV → A + B + C.
Hauv nws, ABC yog thawj qhov sib xyaw ua ke uas tau tawg lawm. A, B thiab C yog cov khoom tsim los ntawm ABC atoms thaum cov tshuaj tiv thaiv decomposition.
Yam kev tawm tsam kev tawm tsam
Raws li tau hais los saum toj no, txhawm rau pib cov txheej txheem tshuaj, nws yog qhov yuav tsum tau muaj qee yam cuam tshuam rau cov tshuaj reagents. Nyob ntawm seb hom kev txhawb nqa zoo li no, muaj ntau ntau hom decomposition:
- YBiodegradation (biological degradation). Nws lub ntsiab lus yog nyob rau hauv kev rhuav tshem ntawm cov complex compounds rau hauv cov yooj yim sawv daws yuav nyob rau hauv tus ntawm cov kab mob nyob (microorganisms). Ib qho piv txwv ntawm cov txheej txheem no tuaj yeem rotting lossis decomposition ntawm cov khib nyiab.
- Thermolysis yog qhov kev puas tsuaj ntawm cov khoom nyob rau hauv kev cuam tshuam ntawm qhov kub thiab txias. Cov tsiaj no muaj ib tug subspecies - pyrolysis. Nyob rau hauv cov tshuaj tiv thaiv decomposition ntawm hom no, rau nws txoj kev siv, cov tshuaj tsis yog tsuas yog rhuab, tab sis kuj deprived ntawm kev nkag mus rau oxygen thiab lwm yam oxidizing neeg sawv cev rau lawv.
- Electrolysis yog kev sib cais ntawm cov tebchaw nrog kev pab ntawm hluav taws xob tam sim no.
- Radiolysis - kev lwj ntawm cov teeb meem nyob rau hauv lub zog ntawm ionizing hluav taws xob. Los ntawm txoj kev, cov txheej txheem no yog siv nquaghauv radiotherapy.
- Solvolysis - qhov tshuaj tiv thaiv no tuaj yeem suav tias yog lub sijhawm tseem ceeb ntawm kev sib cais thiab kev sib pauv (AB + VG → AG + BV). Txawm hais tias nws ua rau kev sib cais ntawm cov tebchaw nyuaj rau hauv cov yooj yim nyob rau hauv lub zog ntawm cov kuab tshuaj, tso tawm atoms ntawm thawj reagent cuam tshuam tsis tau tsuas yog nrog ib leeg, tab sis kuj nrog cov catalyst. Nyob ntawm nws cov ntsiab lus, peb hom kev sib cais ntawm kev sib cais yog qhov txawv: alcoholysis (alcohols - ROH), hydrolysis (dej - H2O) thiab ammonolysis (ammononia - NH3).
Cov tshuaj tiv thaiv decomposition ntawm poov tshuaj permanganate (KMnO4)
Tau nrog txoj kev xav, nws tsim nyog xav txog cov piv txwv ntawm cov txheej txheem ntawm kev faib cov tshuaj.
Thawj ntawm cov no yuav lwj ntawm KMnO 4 (feem ntau hu ua potassium permanganate) vim cua sov. Cov tshuaj tiv thaiv kab zauv rau kev decomposition ntawm poov tshuaj permanganate zoo li no:+ MnO2 + O2↑.
Los ntawm cov qauv tshuaj uas tau nthuav tawm nws tuaj yeem pom tau tias txhawm rau qhib cov txheej txheem, nws yog qhov yuav tsum tau ua kom sov thawj zaug rau 200 degrees Celsius. Rau cov tshuaj tiv thaiv zoo dua, poov tshuaj permanganate muab tso rau hauv lub tshuab nqus tsev. Los ntawm qhov no peb tuaj yeem xaus tias cov txheej txheem no yog pyrolysis.
Hauv chav kuaj thiab hauv kev tsim khoom, nws tau ua kom tau txais cov pa ntshiab thiab tswj tau.
Thermolysis ntawm potassium chlorate (KClO3)
Cov tshuaj tiv thaiv decomposition ntawm Berthollet ntsev yog lwm qhov piv txwv ntawm classical thermolysis hauvntshiab.
Cov txheej txheem hais los ntawm ob theem thiab zoo li no:
- 2 KClO3 (t 400 °C) → 3KClO4 + KCl.
- KClO4 (t ntawm 550 °C) → KCl + 2O2
Tsis tas li, thermolysis ntawm potassium chlorate tuaj yeem ua tiav ntawm qhov kub qis (txog 200 ° C) hauv ib theem, tab sis qhov no yuav tsum muaj cov tshuaj catalyzing koom nrog cov tshuaj tiv thaiv - oxides ntawm ntau yam hlau (khob, ferum, manganese, thiab lwm yam..p.).
Ib qhov sib npaug ntawm qhov zoo li no: 2KClO 3 (t 150 °С, MnO 2) → KCl + 2O2.
Zoo li poov tshuaj permanganate, Bertolet ntsev yog siv hauv chav kuaj thiab kev lag luam los tsim cov pa ntshiab.
Electrolysis thiab radiolysis ntawm dej (H20)
Ib qho piv txwv zoo tshaj plaws ntawm cov tshuaj tiv thaiv raws li kev txiav txim siab yog qhov decomposition ntawm dej. Nws tuaj yeem ua tau ob txoj hauv kev:
- Raws li cov hluav taws xob tam sim no ntawm hydrogen oxide: H2O → H2↑ + O2 ↑. Txoj kev txiav txim siab kom tau txais cov pa oxygen yog siv los ntawm submariners ntawm lawv cov submarines. Tsis tas li ntawd yav tom ntej nws tau npaj siv nws los tsim cov hydrogen ntau. Qhov teeb meem tseem ceeb rau hnub no yog cov nqi hluav taws xob loj loj uas yuav tsum tau ua kom muaj kev tawm tsam. Thaum pom ib txoj hauv kev kom txo tau lawv, dej electrolysis yuav dhau los ua txoj hauv kev tsim tsis yog hydrogen xwb, tab sis kuj muaj oxygen.
- Koj tuaj yeem faib dej thaum raug hluav taws xob alpha: H2O → H2O++e-. Yog li ntawd, hydrogen oxide molecule poob ib lub electron, ua ionized. Nyob rau hauv daim ntawv no, H2O+ dua reacts nrog lwm cov dej nruab nrab molecules, tsim ib tug heev reactive hydroxide radical: H2O+ H2O+→ H2O + OH. Cov hluav taws xob ploj, dhau los, kuj ua rau tib lub sijhawm nrog cov nruab nrab hydrogen oxide molecules, ua rau lawv lwj mus rau H thiab OH radicals: H2O + e-→ H + OH.
Cleavage of alkanes: methane
Xav txog ntau txoj hauv kev ntawm kev sib cais cov tshuaj nyuaj, nws tsim nyog them nyiaj tshwj xeeb rau cov tshuaj tiv thaiv decomposition ntawm alkanes.
Lub npe no zais saturated hydrocarbons nrog cov qauv dav dav CXH2X+2. In cov molecules ntawm cov tshuaj nyob rau hauv kev txiav txim siabtag nrho cov pa roj carbon atoms txuas nrog ib daim ntawv cog lus.
Cov neeg sawv cev ntawm cov koob no muaj nyob rau hauv qhov xwm txheej hauv peb lub xeev ntawm kev sib sau ua ke (gas, kua, khoom).
Txhua alkanes (cov tshuaj tiv thaiv decomposition ntawm cov neeg sawv cev ntawm cov koob no hauv qab no) yog sib dua li dej thiab tsis yaj hauv nws. Txawm li cas los xij, lawv tus kheej yog cov kuab tshuaj zoo heev rau lwm cov tebchaw.
Ntawm cov tshuaj tseem ceeb ntawm cov khoom xws li (combustion, hloov pauv, halogenation, dehydrogenation) - thiab muaj peev xwm sib cais. Txawm li cas los xij, cov txheej txheem no tuaj yeem ua tiav tag nrho lossis ib nrab.
Cov cuab yeej saum toj no tuaj yeem txiav txim siab ntawm qhov piv txwv ntawm cov tshuaj tiv thaiv decomposition ntawm methane (thawj tus tswv cuab ntawm alkane series). Qhov ntsuas kub no tshwm sim ntawm 1000°C: CH4↑ → C+2H2↑.
Txawm li cas los xij, yog tias cov tshuaj tiv thaiv methane decomposition tau ua tiav ntawm qhov kub siab dua (1500 ° C), thiab tom qab ntawd nws txo qis, cov roj no yuav tsis tawg tag, tsim ethylene thiab hydrogen: 2CH 4 ↑ → C2H4↑ + 3H2↑.
Ethane decomposition
Tus tswv cuab thib ob ntawm alkane series hauv kev txiav txim siab yog С2Н4(ethane). Nws cov tshuaj tiv thaiv decomposition kuj tshwm sim nyob rau hauv lub siab kub (50 ° C) thiab nyob rau hauv tag nrho tsis muaj oxygen los yog lwm yam oxidizing neeg sawv cev. Zoo li no: C2H6↑ → C2H4 ↑ + H2↑.
Cov lus sib npaug saum toj no rau kev sib cais ntawm ethane rau hydrogen thiab ethylene tsis tuaj yeem suav tias yog pyrolysis ntshiab. Qhov tseeb yog tias cov txheej txheem no tshwm sim nrog lub xub ntiag ntawm cov catalyst (piv txwv li, nickel hlau Ni los yog dej vapor), thiab qhov no contradicts lub ntsiab lus ntawm pyrolysis. Yog li ntawd, nws yog qhov tseeb los hais txog kev sib cais piv txwv uas tau hais los saum toj no raws li cov txheej txheem decomposition uas tshwm sim thaum pyrolysis.
Nws tsim nyog sau cia tias qhov kev txiav txim siab hauv kev lag luam tau siv dav kom tau txais cov khoom siv organic ntau tshaj plaws hauv ntiaj teb - ethylene gas. Txawm li cas los xij, vim yog qhov tawg ntawm C2H6no alkene yooj yim tshaj plaws yog synthesized los ntawm lwm yam. tshuaj.
Tom qab txiav txim siab cov ntsiab lus, qhov sib npaug, hom thiab ntau yam piv txwv ntawm kev cuam tshuamdecomposition, peb tuaj yeem xaus tias nws ua lub luag haujlwm tseem ceeb tsis yog rau tib neeg lub cev thiab xwm, tab sis kuj rau kev lag luam. Tsis tas li ntawd, nrog rau nws cov kev pab, ntau yam muaj txiaj ntsig zoo tuaj yeem ua ke hauv cov chaw sim, uas pab cov kws tshawb fawb los ua cov kev tshawb fawb tshuaj tseem ceeb.
