Qauv thiab molecular mis: acetylene

2024 Tus sau: Angel Austin | [email protected]. Kawg hloov kho: 2023-12-17 05:28

Cov yam ntxwv ntawm acetylene cuam tshuam rau nws cov khoom, ntau lawm thiab siv. Lub cim rau cov muaj pes tsawg leeg ntawm ib yam khoom - С₂Н₂ - yog nws cov qauv yooj yim thiab tag nrho. Acetylene yog tsim los ntawm ob lub pa roj carbon atom, ntawm qhov kev sib cog lus triple tshwm sim. Nws lub xub ntiag yog tshwm sim los ntawm ntau hom qauv thiab qauv ntawm ethine molecule, uas ua rau nws muaj peev xwm nkag siab txog qhov teeb meem ntawm kev cuam tshuam ntawm cov qauv ntawm cov khoom ntawm ib yam khoom.

Alkynes. General formula. Acetylene

Alkyne hydrocarbons, los yog acetylenic hydrocarbons, yog acyclic, unsaturated. Cov saw hlau ntawm carbon atoms tsis raug kaw; nws muaj ib qho thiab ntau daim ntawv cog lus. Cov muaj pes tsawg leeg ntawm alkynes yog reflected nyob rau hauv cov ntsiab lus formula C H_{2n – 2}. Molecules ntawm cov khoom ntawm chav kawm no muaj ib lossis ntau dua triple bonds. Acetylene compounds yog unsaturated. Qhov no txhais tau hais tias tsuas yog ib qho valence ntawm carbon yog pom tau hais tias tus nqi ntawm hydrogen. Peb daim ntawv cog lus ntxiv yog siv thaum cuam tshuam nrog lwm cov pa roj carbon atoms.

Thawj - thiab nto moo tshaj plaws sawv cev ntawm alkynes - acetylene, los yog ethyl. Lub npe tsis tseem ceeb ntawm cov tshuaj los ntawm lo lus Latin "acetum" - "vinegar" thiabGreek - "hyle" - "ntoo". Cov poj koob yawm txwv ntawm homologous series tau pom nyob rau xyoo 1836 hauv kev sim tshuaj, tom qab ntawd cov tshuaj tau tsim los ntawm cov thee thiab hydrogen los ntawm E. Davy thiab M. Berthelot (1862). Ntawm qhov kub thiab txias atmospheric siab, acetylene nyob rau hauv lub xeev gaseous. Nws yog cov roj tsis muaj xim, tsis muaj ntxhiab, me ntsis soluble hauv dej. Ethine yaj yooj yim dua hauv ethanol thiab acetone.

Molecular formula ntawm acetylene

Etin yog tus tswv cuab yooj yim tshaj plaws ntawm nws cov homologous series, nws muaj pes tsawg leeg thiab cov qauv qhia txog cov qauv:

1. С₂Н₂ - ethine muaj pes tsawg leeg molecular cov ntaub ntawv, uas muab lub tswv yim tias cov khoom yog tsim los ntawm ob lub carbon atoms thiab cov tib tus naj npawb ntawm hydrogen atoms. Siv cov qauv no, koj tuaj yeem xam cov molecular thiab molar masses ntawm cov compound. Mr (С₂Н₂)=26 a. e.m., M (С₂Н₂)=26.04 g/mol.
2. Н:С:::С:Н - electron point formula of acetylene. Xws li cov duab, hu ua "Lewis structures", muaj kev cuam tshuam cov qauv hluav taws xob ntawm cov molecule. Thaum sau ntawv, nws yog ib qho tsim nyog yuav tau ua raws li cov cai: hydrogen atom, thaum tsim ib daim ntawv cog lus tshuaj, zoo li muaj kev teeb tsa ntawm helium valence plhaub, lwm yam ntsiab lus - octet ntawm sab nraud electrons. Txhua txoj hnyuv txhais tau tias yog ib qho ntawm ob lub atoms lossis ib khub ntawm electrons ntawm lub zog sab nraud.
3. H-C≡C-H - qauv qauv ntawm acetylene, xav txog qhov kev txiav txim thiab ntau qhov sib txuas ntawm cov atoms. Ib tug dash hloov ib khub ntawm electrons.

Acetylene molecule qauv

Formula uas qhia txog kev faib cov hluav taws xob ua lub hauv paus rau kev tsim cov qauv atomic orbital, spatial qauv ntawm molecules (stereochemical). Thaum ntxov thaum xaus ntawm lub xyoo pua 18th, cov qauv pob-thiab-loj tau nthuav dav - piv txwv li, pob ntawm cov xim sib txawv thiab qhov ntau thiab tsawg, qhia txog carbon thiab hydrogen, uas tsim acetylene. Cov qauv qauv ntawm cov molecule yog nthuav tawm nyob rau hauv daim ntawv ntawm rods, symbolizing cov tshuaj bonds thiab lawv cov naj npawb nyob rau hauv txhua atom.

Cov qauv pob-thiab-loj ntawm acetylene rov tsim cov duab sib npaug sib npaug li 180 °, tab sis qhov sib txawv ntawm qhov sib txawv hauv cov molecule tau cuam tshuam kwv yees li. Cov voids ntawm cov npas tsis tsim ib lub tswv yim ntawm kev sau qhov chaw ntawm atoms nrog electron ceev. Qhov tsis zoo yog tshem tawm hauv Dreiding cov qauv, uas xaiv lub nuclei ntawm atoms tsis yog cov pob, tab sis raws li cov ntsiab lus ntawm kev txuas ntawm cov pas nrig rau ib leeg. Cov qauv ntim niaj hnub no muab cov duab pom tseeb ntawm atomic thiab molecular orbitals.

Acetylene hybrid atomic orbitals

Carbon nyob rau hauv lub xeev zoo siab muaj peb p-orbitals thiab ib qho nrog unpaired electrons. Hauv kev tsim cov methane (CH ₄₎ lawv koom nrog hauv kev tsim cov ntawv sib npaug nrog hydrogen atoms. Tus kws tshawb fawb Asmeskas nto moo L. Pauling tau tsim cov lus qhuab qhia ntawm hybrid xeev ntawm atomic orbitals (AO). Kev piav qhia ntawm tus cwj pwm ntawm cov pa roj carbon monoxide hauv cov tshuaj lom neeg yog kev sib tw ntawm AO hauv daim ntawv thiab lub zog, tsim cov huab tshiab. hybridorbitals muab cov ntawv cog lus muaj zog, cov qauv ua kom ruaj khov.

Carbon atoms nyob rau hauv acetylene molecule, tsis zoo li methane, undergo sp-hybridization. Cov s- thiab p electrons yog sib xyaw ua ke hauv cov duab thiab lub zog. Ob lub sp-orbitals tshwm sim, dag ntawm lub kaum sab xis ntawm 180 °, taw qhia rau sab nraud ntawm lub nucleus.

Triple bond

Hauv acetylene, hybrid electron huab cua ntawm carbon koom nrog tsim σ-bonds nrog tib lub atoms nyob sib ze thiab nrog hydrogen hauv C-H khub. Tseem muaj ob qhov tsis yog-hybrid p-orbitals perpendicular rau ib leeg. Nyob rau hauv lub ethine molecule, lawv koom nyob rau hauv tsim ntawm ob π bonds. Ua ke nrog σ, ib daim ntawv cog lus triple tshwm sim, uas yog cuam tshuam los ntawm cov qauv qauv. Acetylene txawv ntawm ethane thiab ethylene los ntawm qhov kev ncua deb ntawm cov atoms. Ib daim ntawv cog lus triple luv dua li ob daim ntawv cog lus, tab sis muaj lub zog loj dua thiab muaj zog dua. Qhov siab tshaj plaws ntawm σ- thiab π-bonds yog nyob rau hauv cheeb tsam perpendicular, uas ua rau tsim ib lub cylindrical electron huab.

Txhim kho cov tshuaj tiv thaiv hauv acetylene

Lub ethine molecule muaj ib tug linear duab, uas ntse qhia txog cov tshuaj formula ntawm acetylene - H-C≡C-H. Cov pa roj carbon thiab hydrogen atoms nyob ntawm ib txoj kab ncaj nraim, 3 σ- thiab 2 π-bonds tshwm ntawm lawv. Dawb txav, kev sib hloov raws C-C axis yog tsis yooj yim sua, qhov no yog tiv thaiv los ntawm lub xub ntiag ntawm ntau daim ntawv cog lus. Lwm cov txiaj ntsig triple:

• ntau tus khub ntawm electrons uas khi ob lub atoms - 3;
• length - 0.120 nm;
• break zog - 836kJ/mol.

Rau kev sib piv: hauv ethane thiab ethylene molecules, qhov ntev ntawm ib leeg thiab ob daim ntawv cog lus tshuaj yog 1.54 thiab 1.34 nm, raws li, C-C so zog yog 348 kJ / mol, C=C - 614 kJ / mol.

Acetylene homologues

Acetylene yog tus neeg sawv cev yooj yim tshaj plaws ntawm alkynes, nyob rau hauv cov molecules uas kuj muaj peb daim ntawv cog lus. Propyne CH₃C≡CH yog acetylene homologue. Cov mis ntawm tus neeg sawv cev thib peb ntawm alkynes - butyne-1 - yog CH₃CH₂C≡CH. Acetylene yog lub npe tsis tseem ceeb rau ethine. Cov txheej txheem nomenclature ntawm alkynes ua raws li IUPAC cov cai:

• nyob rau hauv linear molecules, lub npe ntawm cov saw tseem ceeb yog qhia, uas tshwm sim los ntawm Greek tus lej, uas lub ntsiab lus -in thiab tus naj npawb ntawm cov atom ntawm triple daim ntawv cog lus ntxiv, piv txwv li, ethyl, propyne., butyne-1;
• tus lej ntawm cov saw tseem ceeb ntawm atoms pib los ntawm qhov kawg ntawm cov molecule ze tshaj rau daim ntawv cog lus triple;
• rau branched hydrocarbons, ua ntej los lub npe ntawm sab ceg, ces lub npe ntawm lub ntsiab saw ntawm atoms nrog cov lus -in.
• qhov kawg ntawm lub npe yog tus lej qhia qhov chaw nyob hauv peb daim ntawv cog lus molecule, piv txwv li, butyne-2.

Isomerism ntawm alkynes. Kev vam meej ntawm cov khoom ntawm tus qauv

Ethine thiab propyne tsis muaj triple daim ntawv cog lus txoj haujlwm isomers, lawv tshwm sim pib nrog butyne. Carbon skeleton isomers muaj nyob rau hauv pentine thiab homologues tom qab nws. Nrog rau kev sib raug zoo triple, tsis muaj spatialisomerism ntawm acetylenic hydrocarbons.

thawj 4 homologues ntawm ethine yog cov pa roj uas tsis zoo hauv dej. Acetylene hydrocarbons C₅ - C₁₅ - kua. Cov khib nyiab yog ethine homologues, pib nrog cov hydrocarbon C₁₇. Cov tshuaj lom neeg ntawm alkynes yog cuam tshuam los ntawm triple daim ntawv cog lus. Hydrocarbons ntawm hom no muaj zog ntau dua li cov ethylene, lawv txuas ntau yam. Cov cuab yeej no yog lub hauv paus rau kev siv dav ntawm ethine hauv kev lag luam thiab thev naus laus zis. Thaum hlawv cov acetylene, cov cua kub ntau tawm, uas yog siv rau hauv cov roj txiav thiab vuam ntawm cov hlau.