Benzene - ib tug ... yam ntxwv mis, lub zog thiab zus tau tej cov benzene

A compound xws li benzene, Ms. Science News for KIDS rau nws ua liaj ua teb tau thaum kawg mas yuav kis tau xwb nyob rau hauv Hlis Ntuj xyoo 1833. Benzene - ib tug compound uas muaj ib tug luv luv-tempered, peb yuav hais, txawm heev. Raws li nws yog pom tawm?

zaj dabneeg

Johann Glauber muab nws lub xim rau cov kev twb kev txuas nyob rau hauv 1649, uas yog tsim nyob rau ntse thaum lub chemist koom nyob rau hauv kev ntawm cov thee ib. Tab sis nws nyiam mus nyob twj ywm incognito.

Tom qab hais txog 170 xyoo, thiab yuav tsum tau ntau npaum li cas leej, nyob rau hauv nruab nrab-twenties ntawm lub XIX xyoo pua, los ntawm lub caij ntawm illuminating roj, namely los ntawm lub cais condensate rho benzene. Yog li ntawd lub dag zog ntawm noob neej tshuav nqi rau Michael Faraday, tus paub txog ntawm ces.

Lub baton rau lub tshaaj ntawm benzene kev cuam tshuam German Eylgard Mitscherlich. Qhov no tshwm sim thaum qhov kev ntawm dhau anhydrous benzoic acid calcium ntsev. Tej zaum, yog li ntawd, peb tau muab ib lub npe kev twb kev txuas - benzene. Tseem, raws li ib qho kev xaiv, tus zaum hu nws roj av. Xyab, Yog hais tias nyob rau hauv Arabic.

Benzene beautifully thiab luj lug zes, nyob rau hauv kev twb kev txuas nrog cov tswvyim Ogyust Loran qhia mus hu nws "cov plaub hau" los yog "benzene". Kaj, ci ntsa iab - yog hais tias txhais los ntawm Greek.

Raws li lub tswv yim ntawm Linus Pauling, lub tswvyim ntawm qhov kev sib txuas lus, ntawm lub zoo ntawm benzene, ib tus paub txog muab compound molecule raws li nram no. Qhov no hexagon. Nws yog inscribed voj voog. Lub foregoing qhia tias cov kev ncaj ncees ntawm lub tshuab hluav taws xob huab ntawm benzene, uas ntse xaus rau (tsis muaj kev zam) carbon voj voog. Sib raug zoo binary kev sib raug zoo muaj cai.

Nrog benzene yav tas los ua hauj lwm raws li ib tug hnyav. Thiab yeej, raws li lawv hais, yog tsis muab kev koom tes, kuv twb tsis muab kev koom tes. Tab sis nws yog nyob rau hauv lub XIX caug xyoo. Nyob rau hauv XX xyoo pua muaj tau teeb meem loj cov kev hloov. benzene zog qhia cov nqi tshaj plaws qualities uas pab nws ua ntau thiab ntau nrov. Lub octane tooj, uas muaj pov thawj siab, muab ib lub sij hawm mus siv nws li roj hais txog fueling tsheb. Qhov kev ua lub impetus uas nws kim heev kev tshem tawm ntawm benzene, extraction ntawd yog nqa tawm raws li ib tug thib ob cov khoom raug coking hlau.

Los ntawm lub forties nyob rau hauv lub teb ntawm tshuaj benzene pib yuav tsum tau consumed nyob rau hauv zus tau tej cov tshuaj uas sai sai tawg. XX xyoo pua crowned nws tus kheej hais tias cov refining kev lag luam tau tsim raws li benzene, uas tau ua rau muab cov tshuaj ua lag luam.

benzene Feature

Unsaturated hydrocarbons yog heev uas zoo sib xws rau benzene. Piv txwv li, ib tug ethylene series hydrocarbon characterizes nws tus kheej raws li lub unsaturated hydrocarbon. Nws yog yus muaj los ntawm ib qho ntxiv cov tshuaj tiv thaiv. Benzene nkag nkag mus rau rau hauv hloov tshua. Tag nrho cov no ua tsaug rau cov atoms uas yog nyob rau hauv tib lub dav hlau. Thiab raws li ib tug qhov tseeb - conjugated electron huab.

Yog hais tias cov mis yog tam sim no nyob rau hauv ib tug benzene nplhaib, ces ib tug yuav tuaj mus rau yooj yim xaus li no - benzene, lub yam ntxwv mis ntawm uas zoo raws nraim tib yam nkaus.

lub zog

Benzene - ib tug ua kua uas muaj tsis muaj xim, tab sis nws muaj ib tug tsis muaj hmoo tsw. Benzene melts thaum kub nce mus txog 5,52 degrees Celsius. Boils ntawm 80,1. Ceev yog 0,879 g / cm ^3, ib tug hniav puas loj sib npaug zos rau 78,11 g / mol. Nyob rau hauv combustion haus luam yeeb ntau. Nws generates heev tebchaw, thaum huab cua penetrates. Fais fab organic hom (benzene, ether, thiab lwm yam) nrog cov piav tshuaj yog kev cob cog rua tsis muaj teeb meem. Nws tsim azeotropic compound nrog dej. Cua sov ua ntej vaporization tshwm sim nyob rau 69,25 degrees (91% benzene). Thaum 25 degrees Celsius yuav ua neej nyob rau hauv dej 1,79 g / L.

tshuaj zog

Benzene yog reacted nrog sulfuric acid thiab nitric acid. Thiab kuj nrog alkenes, halogens, chloroalkanes. hloov cov tshuaj tiv thaiv - uas yog peculiar rau nws. Kub muaj feem xyuam rau lub siab txhob benzene nplhaib uas extends nyob rau hauv ib tug ncaj hnyav tej yam kev mob.

Txhua kab zauv ntawm cov tshuaj tiv thaiv ntawm benzene peb yuav pom tau ntau yam.

1. Electrophilic hloov chaw. Bromo, nyob rau hauv lub xub ntiag ntawm ib lub hauv paus, yog reacted nrog chlorine. Cov no ib tug chlorobenzene:

C6H6 + 3Cl2 → C6H5Cl + HCl

2. Friedel-Crafts cov tshuaj tiv thaiv los yog alkylation ntawm benzene. Lub rov tshwm sim ntawm alkylbenzenes yuav siv sij hawm qhov chaw vim lub kev twb kev txuas nrog alkanes, uas yog halogen derivatives:

C6H6 + C2H5Br → C6H5C2H5 + HBr

3 Electrophilic hloov chaw. Ntawm no yog cov tshuaj tiv thaiv ntawm nitration thiab sulfonation. Saib benzene kab zauv raws li nram no:

C6H6 + H2SO4 → C6H5SO3H + H2O

C6H6 + HNO3 → C6H5NO2 + H2O

4. Benzene thaum lub sij hawm combustion:

2C6H6 + 15O2 → 12CO2 + 6H2O

Nyob rau hauv tej yam tej yam kev mob, nws exhibits ib tug xwm xam qhovkev noo hydrocarbons. U-electron huab, uas yog nyob rau hauv cov qauv ntawm cov tshuaj yeeb dej caw nyob rau hauv lo lus nug, piav txog txoj kev tshua.

Los ntawm tshwj xeeb technology nyob ntawm seb ntau hom benzene. Li no tus npav ntawm cov roj av benzene. Piv txwv li, mas kev dawb huv thiab purification rau lub synthesis. Kuv xav muab khi qhov homologues ntawm benzene, thiab yog hais tias lub pob zeb - lawv tshuaj zog. Nws alkylbenzenes.

Homologues ntawm benzene yog ntau npaum li cas yuav teb cov lus. Tab sis lub aforementioned tshuaj tiv thaiv ntawm benzene, namely homologues dhau nrog ib co sib txawv.

halogenation ntawm alkylbenzenes

Daim ntawv ntawm cov kab zauv yog raws li nram no:

S6H5-CH3 + Br = C6H5-CH2Br + HBr.

Lub siab xav bromine nyob rau hauv lub benzene nplhaib yog tsis cai. Nws nkag mus rau hauv lub sab saw. Tab sis ua tsaug ntsev catalyst Al (+3) bromo ua siab loj nyob rau hauv lub nplhaib.

nitration ntawm alkylbenzenes

Vim sulfuric thiab nitric acids, nitrating benzenes thiab alkyl benzenes. Reactive alkyl benzenes. Ob khoom uas tau los ntawm peb lub hais - ib tug para- thiab ortho-isomers. Koj muaj peev xwm sau ib tug ntawm cov qauv:

C6H5 - CH3 + 3HNO3 → C6H2CH3 (NO2) 3.

oxidation

Benzene yog tsis tsim nyog. Tab sis alkyl benzenes hnov mob nkag. Piv txwv li, benzoic acid. Cov mis yog raws li nram no:

C6H5CH3 + [O] → C6H5COOH.

Alkylbenzene thiab benzene, hydrogenation ntawm

Nyob rau hauv lub xub ntiag ntawm hydrogen amplifier pib hnov mob nrog benzene, yog li tsim cyclohexane, raws li tau sib tham txog saum toj no. Ib yam li ntawd alkibenzoly seamlessly hloov dua siab tshiab rau hauv alkylcyclohexanes. Rau alkylcyclohexane yuav tsum tau raug mus rau lub yam alkyl benzene hydrogenation. Yeej nws yog ib tug tsim nyog txoj kev zus tau tej cov unalloyed khoom. Thiab qhov no yog tsis yog txhua txhua cov tshuaj tiv thaiv ntawm benzene thiab alkyl benzene.

Qhuav ntawm benzene. kev lag luam

Fundam xws ntau lawm yog raws li nyob rau hauv lub fact tias cov recycle Cheebtsam: toluene, naphtha ib uas yog tso tawm thaum lub sij hawm cracking ntawm thee, thiab lwm yam. Yog li ntawd, benzene yog ua nyob rau hauv petrochemical, metallurgical qhauj. Nws yog ib qho tseem ceeb kom paub tias yuav ua li cas kom tau txawv benzene purity, vim hais tias ntawm lub hauv paus ntsiab lus ntawm ntau lawm thiab cov lo lus uas yuav tsum tau ib tug ncaj qha kev sib raug zoo ntawm cov hom ntawm tus tshuaj.

Tus tsov ntxhuav lub sib qhia yog ua reforming catalytic hlaws feem kaustobiolitnoy hau tawm ntawm 65 degrees, uas muaj cov nyhuv ntawm extract distillation nrog dimethylformamide.

Nyob rau hauv ua ethylene thiab propylene yog tau kua cov khoom uas yog tsim nyob rau thaum lub sij hawm lwj ntawm inorganic thiab organic tebchaw, nyob rau hauv tus ntawm tshav kub. Ntawm no, benzene thiab raug rho tawm. Tab sis, Tu siab, lub raw khoom rau zus tau tej version ntawm lub benzene yog tsis yog li ntawd ntau npaum li cas. Vim hais tias peb xav nyob rau hauv lub tshuaj rho tawm los ntawm reforming. Los ntawm xws li ib tug txoj kev tsub kom tus nqi ntawm cov benzene.

Los ntawm dealkylation ntawm 610-830 degrees nrog ib tug ntxiv kos npe rau, nyob rau hauv lub xub ntiag ntawm vapor tsim thaum lub sij hawm boiling ntawm cov dej thiab hydrogen, yog npaj los ntawm toluene, benzene. Muaj lwm cov kev xaiv - ib lub hauv paus. Thaum lub xub ntiag ntawm zeolites tshwm sim, los yog hloov, oxide catalysts, kev kawm mus rau kub 227-627 degrees.

Muaj lwm, cov laus, txoj kev loj hlob benzene. Nrog tus haum ntawm cov organic keeb kwm tog nws yog cais los ntawm zaum kawg tshwm sim ntawm coking thee. Cov khoom twb raug mus rau chav-roj thiab pre-cua txias. Piv txwv li, nyob rau hauv lub chav kawm ntawm embarking roj, uas yog ib qhov chaw ntawm cov roj los yog cov thee. Thaum distillation yog nqa tawm nrog chav, ib tug absorber sib cais. Hydrotreating ntawm crude benzene pab dawb los ntawm ruaj tshuaj.

thee ib raw cov ntaub ntawv

Nyob rau hauv metallurgy siv cov thee, thiab yog hais tias yuav cais puab - nws qhuav distillation muab coke. Thaum lub sij hawm txoj kev ua no, yog tas cua txaus. Tsis txhob hnov qab tias rau ib tug kub ntawm 1200-1500 Celsius kub thee.

Carbon Science News for KIDS benzene yuav tsum tau meej purification. Koj yuav tsum tau tshem ntawm yuav tsum tau los ntawm methyl cyclohexane thiab nws tus khub ntawm n-heptane. Nyeem hydrocarbons yuav tsum tau muab tshem tawm. Benzene mus yuav tus txheej txheem ntawm kev sib cais, purification, uas yuav tsum tau nqa tawm ntau tshaj li ib zaug.

Cov kev piav saum toj no, cov hlob, tab sis tom qab ib lub sij hawm nws loses nws siab txoj hauj lwm.

roj av fractions

0.3-1.2% - cov nuj nqis twb peb hero nyob rau hauv lub kho roj. Tu siab heev ua tau zoo mus sib piv cov nqi thiab nyiaj txiag cov rog. Nws yog qhov zoo tshaj plaws los mus siv ib tug muaj txheej txheem rau cov kev ua ntawm cov roj fractions. Qhov ntawd yog catalytic reforming. Nyob rau hauv lub xub ntiag ntawm txhuas-platinum-rhenium amplifier tau txais ua feem pua ntawm cov uas muaj ntxhiab carbohydrates, thiab tsub kom qhov taw qhia defining nta tsis self-zes roj thaum lub sij hawm nws compression.

pyrolysis cob

Yog hais tias peb extract los ntawm cov roj av nyoos khoom, namely los ntawm pyrolysis ua rau zus tau tej cov propylene thiab ethylene, hais tias qhov no mus kom ze yuav lub feem ntau tsim nyog. Yuav kom leej, benzene tso tawm los ntawm pyrocondensate. Lub decomposition ntawm tej yam shares yuav tsum tau hydrotreating. Thaum tu leej faj thiab unsaturated tshem tawm sib tov. Cov thawj zaug tshwm sim ntawm txheem sau tseg xylene, toluene, benzene. Los ntawm kev tsav tsheb uas yog ekstaktivnym, BTK-pab pawg neeg yog tau thiab yog sib cais benzene.

hydrodealkylation ntawm toluene

Primary Heroes txheej txheem cocktail ntawm hydrogen txaus thiab toluene yog pub mus rau hauv lub rhuab reactor. Toluene twb dhau los ntawm lub catalyst txheej. Thaum lub sij hawm tus txheej txheem no, tus methyl pab pawg neeg yog sib cais tsim benzene. Qhov twg tsim nyog ib txoj kev ntawm purification. Cov no ib tug high-kev coj dawb huv substance (nitration).

toluene disproportionation

Nyob rau hauv qhov tsim nyog tau methyl rejection chav kawm ntawv yog ua los creation benzene, xylene yog oxidized. Nyob rau hauv tus txheej txheem no, nws twb tau cai transalkylation. Qhov kev txiav txim yog vim lub catalyzing palladium, platinum thiab neodymium, uas yog nyob rau hauv lub alumina.

Lub reactor yog resistant mus rau tsim ntawm lub catalyst thiab hydrogen nkag taluol. Nws lub hom phiaj - kom lub deposition ntawm lub hydrocarbon hloov dua siab tshiab catalyst ntawm lub dav hlau. Cov kwj uas nyob rau hauv lub reactor yog txias thiab siv hydrogen yog muab tshem tawm yam xyuam xim. Yuav ua li cas yog sab laug, nws yog distilled peb lub sij hawm. Thaum thawj zaug rau theem rho tebchaw uas tsis yog-uas muaj ntxhiab. Qhov thib ob ua benzene, thiab lub xeem kauj ruam - ib tug faib ntawm xylenes.

trimerization ntawm acetylene

Vim lub chaw ua hauj lwm ntawm Fabkis lub cev chemist Marcellin Berthelot los ntawm acetylene siv steel benzene. Tab sis nws sawv ib tug hnyav cocktail ntawm ntau lwm yam hais. Cov lus nug yog yuav ua li cas los txo cov tshuaj tiv thaiv kub. Cov lus teb twb tau xwb nyob rau hauv lub lig forties ntawm lub XX caug xyoo. W. Reppe pom ib tug haum catalyst, nws muaj pov thawj yuav tsum tau npib tsib xee. Trimerization - yog qhov kev xaiv xwb yuav kis tau los ntawm acetylene benzene.

benzene tsim muaj tshwm sim nrog tshuab txais charcoal. Thaum muaj cov tshav kub tshaj cov thee kis acetylene. Benzene yog tso tawm yog hais tias tus kub yog tsawg kawg yog 410 degrees. Yog li tseem yug los ntau uas muaj ntxhiab hydrocarbons. Yog li ntawd, koj yuav tsum zoo cov khoom, uas muaj peev xwm sawv ntawm qualitatively tseeb acetylene. Nyob rau hauv xws li ib tug lub sij hawm-siv cov txheej txheem raws li cov trimerization ntawm acetylene noj ntau. Yog xav tau kev 15 ml ntawm benzene, 20 litres yog coj acetylene. Koj yuav saib tau npaum li cas nws zoo nyob rau hauv lub mis (acetylene, benzene), cov tshuaj tiv thaiv tsis ntev ntev.

3C2H2 → C6H6 (Zelinsky kab zauv).

3CH → CH = (t, kat) = C6H6.

Qhov twg siv benzene

Benzene - nws yog heev nrov brainchild Science News for KIDS. Tshwj xeeb tshaj yog feem ntau nws tau raug cai raws li benzene tau txais kev pab cuam nyob rau hauv lub chaw ua khoom ntawm cumene, cyclohexane, ethylbenzene. Yuav kom tsim styrene ethylbenzene tsis tau ua tsis tau. Cov pib cov ntaub ntawv uas nyob rau hauv thiaj li yuav ua tus caprolactam yog cyclohexane. Los ntawm kev ua cov thermoplastic cob siv yog caprolactam. Piav ib yam khoom tseem ceeb nyob rau hauv qhov siv thiab ua ntau yam xim, varnishes.

Yuav ua li cas txaus ntshai benzene

Benzene - ib tug tshuaj lom tshuaj. Manifestation ntawm txoj kev xav ntawm malaise, uas yog nrog xeev siab thiab kiv taub hau - ib tug kos npe rau ntawm kev qaug tshuaj lom. Nws yog tsis cais txawm tuag. Ib tug kev xav ntawm indescribable kev kaj siab - nws yog tsis tsawg tswb neeb nyob rau hauv cov ntaub ntawv ntawm kev qaug tshuaj lom los ntawm benzene.

Benzene kua ua daim tawv nqaij voos. Benzene khub niam txiv tau yooj yim mus rau txawm los ntawm lawm daim tawv nqaij. Thaum lub feem ntau luv luv-term kev sib cuag nrog lub tshuaj nyob rau hauv ib tug me me koob tshuaj, tab sis rau ib tug tsis tu ncua, kaj siab txim tsis ntev ntev tos. Qhov no tej zaum yuav hloov hlwb pob txha thiab leukemia mob xwm ntawm ntau hom.

Nyob rau sab saum toj ntawm uas substance yog hom nyob rau hauv tib neeg. Benzene ua raws li Datura. Los ntawm kev haus luam yeeb puv tarry khoom. nws kawm code, ces tuaj mus rau lub xaus hais tias cov ntsiab lus ntawm lub yav tas yog tsis muaj kev nyab xeeb rau cov tib neeg. Nws twb pom nyob rau hauv tas li ntawd mus rau lub xub ntiag ntawm nicotine thiab txawm lub xub ntiag ntawm uas muaj ntxhiab carbohydrates hom benzopyrene. Txwm benzpyrene yog carcinogens. Nyhuv lawv muaj heev teeb meem. Piv txwv li, ua rau mob cancer.

Notwithstanding rau cov foregoing, benzene yog lub pib cov ntaub ntawv uas rau zus tau tej cov ntau yam pharmaceuticals, yas, hluavtaws roj hmab thiab, ntawm chav kawm, pigments. Qhov no yog feem ntau tus me nyuam ntawm Science News for KIDS thiab ib tug uas muaj ntxhiab compound.