Saturated hydrocarbons (paraffins) yog aliphatic hydrocarbons saturated, qhov twg muaj ib qho yooj yim (ib zaug) daim ntawv cog lus ntawm carbon atoms.
Tag nrho lwm qhov valences tau saturated nrog hydrogen atoms.
Hmoob series
Qhov kawg saturated hydrocarbons muaj cov qauv dav dav SpH2p + 2. Raws li ib txwm muaj, cov neeg sawv cev ntawm cov chav kawm no qhia qhov tsis muaj zog reactivity, yog li lawv hu ua "paraffins". Saturated hydrocarbons pib nrog methane, uas muaj cov mis molecular CH4.
Cov qauv nta ntawm qhov piv txwv ntawm methane
Cov khoom siv organic no tsis muaj ntxhiab tsw thiab tsis muaj xim, cov pa roj yuav luag ob zaug lub teeb li huab cua. Nyob rau hauv cov xwm, nws yog tsim thaum lub sij hawm decomposition ntawm cov tsiaj thiab cov nroj tsuag kab mob, tab sis tsuas yog nyob rau hauv tsis muaj huab cua nkag. Nws pom nyob rau hauv cov mines thee, hauv swampy reservoirs. Hauv qhov me me, methane yog ib feem ntawm cov pa roj ntsha, uas tam sim no siv los ua roj hauv kev tsim khoom, hauv lub neej txhua hnub.
Qhov no saturated hydrocarbon yog nyob rau hauv chav kawm ntawm alkanes muaj covalent polar daim ntawv cog lus. Tus qauv tetrahedral tau piav qhia los ntawm sp3hybridization ntawm carbon atom, lub kaum sab xis yog 109 ° 28'.
Nomenclature ntawm paraffins
Saturated hydrocarbons tuaj yeem raug hu ua raws li kev cai nomenclature. Muaj ib txoj kev uas tso cai rau koj mus rau hauv tus account tag nrho cov ceg uas muaj nyob rau hauv lub molecule ntawm saturated hydrocarbon. Ua ntej koj yuav tsum txheeb xyuas cov saw hlau ntev tshaj plaws, tom qab ntawd suav cov carbon atoms. Ua li no, xaiv ib feem ntawm cov molecule uas muaj qhov siab tshaj plaws branching (ntau dua cov radicals). Yog hais tias muaj ob peb zoo tib yam radicals nyob rau hauv lub alkane, qhia prefixes qhia nrog lawv lub npe: di-, tri-, tetra. Cov lej yog siv los qhia meej txog txoj haujlwm ntawm cov khoom nquag hauv hydrocarbon molecule. Cov kauj ruam kawg ntawm lub npe paraffins yog qhov qhia txog cov saw hlau nws tus kheej, nrog rau qhov sib ntxiv ntawm cov lus -an.
Saturated hydrocarbons txawv hauv lawv lub xeev ntawm kev sib sau. Thawj plaub tus neeg sawv cev ntawm lub npe nyiaj ntsuab no yog cov khoom siv roj (los ntawm methane mus rau butane). Raws li qhov txheeb ze molecular hnyav nce, muaj kev hloov pauv mus rau cov kua, thiab tom qab ntawd mus rau lub xeev ntawm kev sib sau ua ke.
Saturated thiab unsaturated hydrocarbons tsis yaj hauv dej, tab sis tuaj yeem yaj hauv cov organic hnyav molecules.
Txoj kev ntawm isomerism
Hom isomerism ua li cas cov hydrocarbons saturated muaj? Piv txwv ntawm cov qauv ntawm cov neeg sawv cev ntawm chav kawm no, pib nrog butane, qhiamuaj isomerism ntawm cov pa roj carbon skeleton.
Cov saw hlau ua los ntawm covalent polar bonds muaj zigzag zoo li. Qhov no yog vim li cas rau kev hloov pauv ntawm cov saw tseem ceeb hauv qhov chaw, uas yog, muaj cov qauv isomers. Piv txwv li, thaum hloov cov kev npaj ntawm atoms nyob rau hauv ib tug butane molecule, nws isomer yog tsim - 2methylpropane.
tshuaj muaj zog
Cia peb xav txog cov khoom siv tshuaj lom neeg ntawm saturated hydrocarbons. Rau cov neeg sawv cev ntawm cov chav kawm ntawm hydrocarbons no, cov tshuaj tiv thaiv ntxiv tsis yog tus yam ntxwv, vim tias txhua daim ntawv cog lus hauv cov molecule yog ib leeg (saturated). Alkanes nkag mus rau hauv kev sib cuam tshuam nrog kev hloov ntawm hydrogen atom los ntawm halogen (halogenation), ib pawg nitro (nitration). Yog tias cov qauv ntawm saturated hydrocarbons muaj daim ntawv SpH2n + 2, tom qab hloov cov khoom ntawm cov muaj pes tsawg leeg CnH2n + 1CL yog tsim, nrog rau CnH2n + 1NO2.
Cov txheej txheem hloov pauv muaj cov txheej txheem dawb radical. Ua ntej, cov khoom nquag (radicals) raug tsim, tom qab ntawd kev tsim cov tshuaj organic tshiab tau pom. Txhua alkanes hnov mob nrog cov neeg sawv cev ntawm xya pawg (pab pawg tseem ceeb) ntawm lub rooj sib tham, tab sis cov txheej txheem tsuas yog nce ntawm qhov kub siab, lossis nyob rau hauv lub xub ntiag ntawm lub teeb quantum.
Tsis tas li, txhua tus neeg sawv cev ntawm methane series yog tus cwj pwm los ntawm kev cuam tshuam nrog cov pa oxygen. Thaum combustion, carbon dioxide thiab dej vapor ua raws li cov khoom siv tshuaj tiv thaiv. Cov tshuaj tiv thaiv yog nrog los ntawm kev tsim ntawm ib qho tseem ceeb ntawm tshav kub.
Thaum methane cuam tshuam nrog oxygen atmosphericKev tawg yog ua tau. Ib qho txiaj ntsig zoo sib xws yog ib txwm muaj rau lwm tus neeg sawv cev ntawm cov chav kawm ntawm saturated hydrocarbons. Yog li ntawd, kev sib xyaw ntawm butane nrog propane, ethane, methane yog qhov txaus ntshai. Piv txwv li, xws li accumululations yog ib yam rau cov thee mines, industrial rhiav. Yog hais tias lub saturated hydrocarbon yog rhuab tshaj 1000 ° C, nws decomposes. Kev kub siab dua ua rau kev tsim cov khoom tsis txaus hydrocarbons, nrog rau kev tsim cov roj hydrogen. Cov txheej txheem dehydrogenation yog qhov tseem ceeb ntawm kev lag luam, nws tso cai rau koj kom tau txais ntau yam ntawm cov organic tshuaj.
Rau hydrocarbons ntawm methane series, pib nrog butane, isomerization yog yam ntxwv. Nws cov ntsiab lus nyob hauv kev hloov cov pob txha pob txha, tau txais saturated branched hydrocarbons.
Daim ntawv thov nta
Methane li cov pa roj ntsha yog siv los ua roj. Chlorine derivatives ntawm methane yog qhov tseem ceeb tshaj plaws. Piv txwv li, chloroform (trichloromethane) thiab iodoform (triiodomethane) yog siv rau hauv cov tshuaj, thiab carbon tetrachloride nyob rau hauv cov txheej txheem ntawm evaporation nres qhov nkag ntawm atmospheric oxygen, yog li nws yog siv los tua hluav taws.
Vim tus nqi siab ntawm tus nqi calorific ntawm hydrocarbons, lawv tau siv los ua roj tsis yog hauv kev tsim khoom, tab sis kuj siv rau hauv tsev.
Ib qho sib xyaw ntawm propane thiab butane, hu ua "liquefied gas", tshwj xeeb tshaj yog nyob rau thaj chaw uas tsis muaj roj av.
Ntiaj teb qhov tseeb
Cov neeg sawv cev ntawm hydrocarbons, uas nyob rau hauv lub xeev ua kua, yog roj rau sab hauv combustion engines nyob rau hauv lub tsheb (gasoline). Tsis tas li ntawd, methane yog ib qho khoom siv pheej yig rau ntau yam kev lag luam tshuaj.
Piv txwv li, cov tshuaj tiv thaiv ntawm decomposition thiab combustion ntawm methane yog siv rau kev lag luam tsim cov kua qaub, uas yog tsim nyog rau kev tsim cov luam ntawv number case, nrog rau kev sib txuas ntawm ntau yam khoom siv roj hmab los ntawm roj hmab.
Yuav ua li cas, xws li ib lub ntim ntawm huab cua nkag mus rau lub cub tawg nrog rau methane kom ib nrab combustion ntawm saturated hydrocarbon tshwm sim. Raws li qhov kub thiab txias, qee qhov methane yuav decompose, ua kom zoo soot.
YKev tsim cov hydrogen los ntawm paraffins
Methane yog lub hauv paus ntawm kev lag luam hydrogen siv rau ammonia synthesis. Txhawm rau ua kom lub cev dehydrogenation, methane yog tov nrog chav.
Cov txheej txheem yuav siv qhov kub ntawm li 400 ° C, lub siab ntawm li 2-3 MPa, aluminium thiab nickel catalysts yog siv. Hauv qee qhov kev sib txuas, kev sib xyaw ntawm cov pa roj yog siv, uas yog tsim nyob rau hauv cov txheej txheem no. Yog tias qhov kev hloov pauv tom ntej no suav nrog kev siv cov ntshiab hydrogen, tom qab ntawd catalytic oxidation ntawm carbon monoxide nrog dej vapor yog nqa tawm.
Chlorination tsim cov khoom sib xyaw ntawm methane chlorine derivatives, uas muaj ntau daim ntawv thov kev lag luam. Piv txwv li, chloromethane muaj peev xwm nqus tau cua sov, uas yog vim li cas nws thiaj li siv los ua cov tub yees hauv cov tub yees niaj hnub no.
Dichloromethane yog cov kuab tshuaj zoo rau cov tshuaj organic, siv hauv tshuaj synthesis.
Hydrogen chloride, tsim nyob rau hauv cov txheej txheem ntawm radical halogenation, tom qab yaj hauv dej, dhau los ua hydrochloric acid. Tam sim no, acetylene kuj tau los ntawm methane, uas yog ib qho tseem ceeb tshuaj raw khoom.
Zoo kawg
Cov neeg sawv cev ntawm methane homologous series tau dav dav hauv cov xwm txheej, uas ua rau lawv nyiam cov tshuaj hauv ntau ceg ntawm kev lag luam niaj hnub no. Los ntawm methane homologues, branched hydrocarbons tuaj yeem tau txais, uas tsim nyog rau kev sib txuas ntawm ntau chav kawm ntawm cov organic. Cov neeg sawv cev siab tshaj plaws ntawm chav kawm alkanes yog cov khoom siv raw rau kev tsim cov tshuaj detergents.
Ntxiv rau paraffins, alkanes, cycloalkanes, hu ua cycloparaffins, kuj muaj txiaj ntsig zoo. Lawv cov molecules kuj muaj cov ntawv cog lus yooj yim, tab sis qhov peculiarity ntawm cov neeg sawv cev ntawm cov chav kawm no yog muaj cov qauv cyclic. Ob leeg alkanes thiab cycloacanes yog siv los ntawm ntau qhov ntau raws li cov pa roj carbon monoxide, vim tias cov txheej txheem yog nrog los ntawm kev tso tawm ntawm cov cua sov (exothermic effect). Tam sim no, alkanes, cycloalkanes suav hais tias yog cov khoom siv tshuaj muaj txiaj ntsig zoo tshaj plaws, yog li lawv cov tswv yim siv tsis txwv rau cov tshuaj tiv thaiv combustion.
