Cov ntsiab lus yooj yim tshaj plaws kawm hauv cov chav kawm chemistry yog cov hydrocarbons saturated lossis paraffins, tseem hu ua alkanes. Lawv qhov zoo muaj pes tsawg leeg yog sawv cev los ntawm cov atom ntawm tsuas yog ob lub ntsiab lus: carbon thiab hydrogen. Molecules ntawm cov tebchaw muaj tsuas yog ib hom tshuaj tiv thaiv - ib leeg, los yog yooj yim. Hauv peb tsab xov xwm, peb yuav kawm cov qauv, nrog rau cov txheej txheem kom tau txais thiab cov khoom ntawm alkanes.
Cov neeg sawv cev ntawm koob thiab lawv lub npe
thawj qhov sib xyaw ntawm cov chav kawm paraffin yog methane. Nws cov mis molecular yog CH4, nws sib raug rau cov qauv ntawm cov tshuaj, uas yog raws li nram no: C H 2 +2. Thawj plaub alkanes muaj cov npe ntawm tus kheej, xws li methane, ethane. Pib los ntawm lub thib tsib compound, lub nomenclature yog tsim los ntawm Greek cov lej. Piv txwv li, ib yam khoom uas muaj tsib carbon atoms nyob rau hauv lub molecule C5H12 yog hu ua pentane (los ntawm Greek lo lus "penta" - tsib). Raws li rational nomenclature, alkanes,Cov khoom siv tshuaj lom neeg thiab kev tsim khoom uas peb tab tom kawm tuaj yeem sawv cev rau hauv daim ntawv ntawm cov tshuaj - derivatives ntawm methane. Hauv nws cov molecule, ib los yog ntau dua hydrogen atoms yog hloov los ntawm hydrocarbon radicals. Raws li qhov systematic nomenclature, koj yuav tsum xaiv cov saw ntev tshaj plaws ntawm cov pa roj carbon atoms, uas yog suav los ntawm qhov kawg uas cov radicals ze dua. Ces tus naj npawb ntawm cov pa roj carbon atom txuas los ntawm ib daim ntawv cog lus sigma rau cov radical particle yog txiav txim, thiab cov radical yog refined los ntawm kev ntxiv lub npe ntawm alkane nws tus kheej rau nws, piv txwv li, 3-methylbutane.
Kev tsim khoom ntawm alkanes
Qhov tseem ceeb thiab feem ntau ntawm cov khoom siv paraffin yog cov ntxhia: cov pa roj thiab roj. Cov kab ntawm methane nrog rau hydrogen thiab nitrogen tuaj yeem pom hauv cov pa nkev. Cov khoom alkanes uas muaj cov pa roj carbon ntau hauv cov molecule muaj nyob hauv ozocerite. Qhov no yog lub roob ciab nrog tag nrho ntau yam ntawm cov khoom tshwj xeeb, cov deposits uas tau tsim, piv txwv li, nyob rau hauv Western Ukraine. Kuj tseem muaj ntau txoj kev siv hluavtaws rau kev rho tawm ntawm cov hydrocarbons saturated, tshwj xeeb, los ntawm kev txo cov tshuaj tiv thaiv. Hauv kev lag luam, ntau txoj hauv kev tuaj yeem paub qhov txawv ntawm kev tsim cov alkanes siv cov tshuaj tiv thaiv redox, piv txwv li, ntawm haloalkyls thiab hydrogen iodide lossis sodium amalgam. Qhov yooj yim dua yog qhov txo qis ntawm alkenes, alkynes lossis alkadienes nrog hydrogen nyob rau hauv muaj cov nickel catalyst. Cov khoom siv tshuaj tiv thaiv yuav yog cov khoom sib txuam paraffin. Cov txheej txheem tuaj yeem qhia los ntawm qhov sib npaug hauv qab noCov tshuaj tiv thaiv:
CH2 =CH2 + H2=H 3C-CH3 (ethane)
Alkaline melting ntawm ntsev ntawm carboxylic acids
Yog tias koj sov sodium ntsev CH3COONa lossis lwm yam khoom ntawm chav kawm no, uas suav nrog cov hlau atoms, nrog sodium hydroxide lossis soda txiv qaub, koj tuaj yeem tau txais cov hydrocarbons saturated. Thawj hom tshuaj tiv thaiv feem ntau yog siv hauv chav kuaj, qhov thib ob yog siv los txheeb xyuas cov qauv ntawm carboxylic acid uas yog ib feem ntawm cov ntsev. Txoj kev tau txais alkanes no tso cai rau koj los saib xyuas qhov sib cais ntawm cov saw hlau ntawm cov reagent thiab qhov txo qis ntawm cov pa roj carbon atoms hauv nws.
Wurtz reaction
Cov tshuaj uas yog derivatives ntawm paraffins, uas hydrogen atoms tau hloov los ntawm cov tshuaj chlorine, bromine los yog iodine, muaj peev xwm cuam tshuam nrog finely dispersed metallic sodium. Qhov sib npaug ntawm cov tshuaj tiv thaiv dav dav yuav yog:
2RHal + 2Na → R-R + 2NaHal, txheej txheem no tau tshawb pom xyoo 1870 los ntawm Fab Kis tus kws tshuaj F. Würz. Tom qab ntawd, P. P. Sharygin qhia meej nws cov txheej txheem ua rau kev tsim cov alkane. Nws muab tawm tias halogen atom yog thawj zaug hloov los ntawm cov hlau. Tom qab ntawd cov txiaj ntsig organosodium cuam tshuam nrog lwm lub haloalkane molecule. Cov tshuaj tiv thaiv no tau pom daim ntawv thov hauv kev siv thev naus laus zis ntawm paraffins ntau dua.
Cov khoom ntawm saturated hydrocarbons
Tus yam ntxwv ntawm lub cev ntawm txhua chav kawm ntawm cov organic tebchaw raug txiav tximcov khoom uas hloov lawm thiab nyob ntawm seb cov qauv ntawm cov molecules ntawm cov khoom. Yog li, thawj plaub homologues ntawm alkanes, cov tshuaj tiv thaiv uas peb xav ua ntej, yog cov pa roj. Paraffins muaj nyob rau hauv lawv cov muaj pes tsawg leeg los ntawm 5 mus rau 14 carbon atoms muaj nyob rau hauv cov kua theem, thaum cov alkanes seem yog cov khoom sib txuas. Gaseous thiab cov khoom muaj ntxhiab tsw, kua paraffins tsw zoo li kerosene lossis roj av. Cov khoom tseem ceeb tshaj plaws ntawm cov khoom muaj xws li, piv txwv li, nyuaj oxidation - combustion, raws li qhov tshwm sim ntawm cov cua kub ntau tawm:
CH4 + 2O2=CO2 + 2H 2O
Nco ntsoov tias methane yog qhov tseem ceeb ntawm cov roj tseem ceeb - natural gas.
Kev hloov pauv hloov pauv
Halogenation pib los ntawm cov dawb radical mechanism yog lwm yam ntawm alkanes. Nws hais txog kev hloov pauv cov tshuaj tiv thaiv thiab ua rau tsim cov tshuaj sib xyaw - halogen derivatives ntawm paraffins:
C5H12+Cl2=HCl + C5 H11Cl (chloropentane).
Nitration yog kev sib cuam tshuam ntawm alkanes nrog dilute nitrate acid nyob rau hauv lub xub ntiag ntawm ib tug catalyst thiab nyob rau hauv lub siab, nrhiav pom nyob rau hauv 1889 los ntawm N. M. Konovalov. Paraffin nitro tebchaw muaj ntau yam kev siv raws li cov ntaub ntawv raw rau kev tsim cov roj foob pob hluav taws, cov khoom tawg, nrog rau kev tshem tawm cov carboxylic acids thiab amines.
Oxidation ntawm cov tswv cuab siab dua ntawm homologous series ntawm alkanes nyob rau hauv lub xub ntiag ntawm ib tug catalyst ua rau zus tau tej cov cawv thiab carboxylicCov kua qaub siv los ua cov khoom siv plasticizers siv hauv kev tsim cov yas thiab cov tshuaj detergents.
Nyob rau hauv peb tsab xov xwm, peb tshuaj xyuas cov khoom ntawm saturated hydrocarbons thiab kawm yuav ua li cas kom tau lawv.
