Chloroform - yog dab tsi? Kev npaj thiab daim ntawv thov kev txiav txim ntawm chloroform

Tus foundations ntawm ntau cov tshuaj tsis yog txhob txwm thiab lo, thaum lub sij hawm lub synthesis, los yog txoj kev kawm ntawm cov khoom ntawm ib yam khoom. Txawm li cas los, muaj ntau tus pheej nrhiav tau cov tshuaj yeeb dej caw yuav tseem ceeb heev, lawv yog siv tsis tau tsuas yog nyob rau hauv Science News for KIDS, tab sis kuj cov tshuaj, kev lag luam thiab lwm yam liaj teb. Cia li nyob rau hauv lub sij hawm rau cov neeg tshuaj thiab lwm yam chloroform, uas yuav tsum tau los sib tham ntxiv.

lub npe

Lub npe ntawm lub substance muaj ob peb ntau yam. Nyob rau hauv qhov tseeb, zoo li tag nrho cov organic tebchaw, nws ua raws li cov kev cai ntawm ntau nomenclature molecules tsis tseem ceeb npe thiab title, raws li nyob rau hauv nyob tus yeees ntawm cov qauv.

Yog li ntawd, mus rau lub chloroform muaj ob peb versions ntawm lub npe:

• carbon trichloride;
• chloroform;
• trichloromethane.

Chloroform: yog dab tsi? Koj yuav qhia tau los ntawm lub title compound, thiab muaj peev xwm xav txog lub geometric qauv ntawm ib tug qauv.

molecular qauv

chloroform molecule muaj peb atoms ntawm cov tshuaj thiab ib tug hydrogen atom, txhua atom yog kev cob cog rua nrog ib tug central carbon. Yeej tseem zoo, trichloromethane molecule - ib tug khoom radical hloov ntawm hydrogen atoms ntawm cov tshuaj atoms nyob rau hauv lub methane molecule thaum raug rau tej yam kev mob.

Nyob rau hauv cov ntaub ntawv no, tag nrho cov C-CL kiag li sib npaug zos, xav ncov qaumteb qabteb. C-H bonds piv mus rau lwm cov bonds tshwm nyob rau hauv lub molecule yuav txawm ntau polarization yuav tsis tshua muaj neeg lam tau lam ua. Yog li ntawd, nyob rau hauv lub ntxiv ua ntawm lub molecule P-H daim ntawv cog lus yog yooj yim nraus thiab hydrogen yog hloov los ntawm lwm cov atoms (e.g., tshuaj chlorine ua, dhau lawm, nrog rau cov tsim ntawm carbon tetrachloride).

Xav txog yuav ua li cas zoo chloroform. Cov mis yog: CHCL _3. Cov yam ntxwv mis ntawm lub nram qab no daim ntawv:

Ob leeg lug sawv cev rau ib yam tshuaj tshuaj uas yog tus chloroform. Cov mis qhia tau hais tias cov molecule yog ruaj khov thiab yuav hnov mob nruj tej yam kev mob yuav tsum tau mus thov.

lub zog

Lub zog muaj peev xwm yuav yus raws li nram no: trichloromethane:

1. Nyob rau hauv tej yam kev mob (chav tsev kub, dab tsi atmospheric siab ntawm 100 kPa, vaum tsis siab tshaj 80%) ntawm cov tshuaj yeeb dej caw yog xav odorous kua muaj tsis muaj xim. Cov tsis hnov tsw ntawm chloroform ntse txaus hnyav, enveloping, zoo li tus ntxhiab tsw ntawm ether. Lub saj ntawm lub qab zib cov khoom, tab sis koj muaj peev xwm tsis sim nws, vim hais tias nws yog tsis tshua muaj tshuaj lom.
2. Cov dej insoluble, muaj peev xwm sawv ntawm dissolving xwb nyob rau hauv ntau hom ntawm cov organic solvents. Txij li thaum dej kuj tsim tau ib cov uas tsis muaj-concentration (0.23%) tov.
3. Lub ib kub npau npau taw tes ntawm no compound yog qis dua hais tias ntawm cov dej yog hais txog 62 ⁰ C.
4. Melting point sharply tsis zoo, -63.5 ⁰ C.
5. Chloroform ceev ntau dua tshaj cov kev ceev ntawm dej thiab nqi 1,483 g / cm ^3.
6. Muaj zog pronounced lom xwm ntawm lub substance rau cov teebmeem nyob ntawm tus kab mob, yog hais txog mus rau ib tug pab pawg neeg ntawm narcotic tebchaw.

Thaum yaj nyob rau hauv dej trehloristy carbon muaj peev xwm ntawm txoj kev azeotropic mixtures. Nyob rau hauv no chloroform tshuaj no yog 97,5% thiab xwb 2.5% dej. Lub ib kub npau npau taw tes ntawm cov tshuaj yog txo piv rau cov ntshiab trichloromethane thiab yog 52 ⁰ C.

tshuaj zog

Zoo li tag nrho cov chlorinated methane, chloroform qhia tau hais tias tsis muaj reactivity. Yog li ntawd, muaj me ntsis cov tshuaj tiv thaiv, raug rau nws. Piv txwv li, kev kho mob ntawm cov tshuaj molecules thaum lub sij hawm tus txheej txheem ntawm kev npaj ntawm derivatives ntawm methane chlorination. Yuav kom qhov no ua kua yog coj chloroform, tshua tshwm sim raws li cov hom radical mechanism yuav tsum tau ultraviolet tawg raws li ib tug prerequisite thiab lub teeb quanta.

CHCL ₃ + CL ₂ = CCL ₄ + HCL

Raws li cov tshuaj tiv thaiv kab zauv qhia tau hais tias cov khoom yog tag nrho chlorinated methane - carbon tetrachloride. Tej tshua yog ib txoj kev muab cov pa roj carbon tetrachloride nyob rau hauv lub lag luam.

Tsis tas li ntawd tshuaj zog muaj xws li azeotropic sib tov nrog dej, uas yog peev xwm ntawm muab chloroform. Yuav ua li cas yog nws? Hais tias yog, xws li ib tug tov ntawm boiling Cheebtsam tsis undergo cov kev hloov. Los ntawm boiling no sib tov yuav tsis raug faib mus rau hauv cov zauv feem.

Lwm yam kev tshua, uas tej zaum yuav nkag mus rau chloroform yog muab los ntawm halogen atoms lwm atoms los yog functional pawg. Piv txwv li, los ntawm cov tshuaj tiv thaiv nrog aqueous sodium hydroxide , nws cov ntaub ntawv sodium acetate:

chloroform + NaOH (aq) = Sodium acetate + Sodium chloride + dej

Tsis tas li ntawd, suab tseem ceeb cov tshuaj tiv thaiv yog cov tshuaj tiv thaiv ntawm chloroform nrog ammonia thiab poov tshuaj hydroxide (feeb meej tov) raws li ib tug ntawm xws li kev sis raug zoo, ib tug cyanide.

Chloroform + ammonia + poov tshuaj hydroxide = KCN + poov tshuaj tshuaj dawb + dej

cia chloroform

Nyob rau hauv lub teeb trichloromethane yog decomposed nrog lub tsim ntawm yus, tshuaj lom cov khoom:

Chloroform phosgene = + hydrochloric acid + tshuaj + molecular carbon dioxide

Yog li ntawd, cov tej yam kev mob ntawm cia ntawm chloroform yuav tsum tshwj xeeb - vials ntawm tsaus iav nrog ib tug nruj stoppered. Raj mis nws tus kheej yuav tsum tau cia kom deb ntawm tshav ntuj.

txais tos

Kev npaj ntawm chloroform twb nqa tawm nyob rau hauv ob peb txoj kev.

1. Ib tug multistage txheej txheem lub chlorination ntawm methane uas tshwm sim los ntawm ib tug radical mechanism nyob rau hauv tus ntawm ultraviolet lub teeb thiab cua sov. Nyob rau hauv cov ntaub ntawv no tshwm sim yog tsis tsuas chloroform, tab sis lwm tus peb cov khoom: chloromethane, dichloromethane thiab cov pa roj carbon tetrachloride. Cov tshuaj tiv thaiv yog raws li nram no:

CH ₄ + CL ₃ = CH ₂ CL + HCL - chloromethane tsim thiab hydrogen chloride

CL + CH ₃ = CH ₂ CL ₂ CL ₂ + HCL - dichloromethane thiab hydrogen chloride tsim

CH ₂ CL ₂ + CL ₂ = CHCL ₃ + HCL - tsim trichloromethane (chloroform), thiab hydrogen chloride

CHCL ₃ + CL ₂ = CCL ₄ + HCL - ntaub ntawv carbon tetrachloride thiab hydrogen chloride

Nyob rau hauv no, lub synthesis trichloromethane kev lag luam.

2. Cov kev sis raug zoo ntawm cov tshuaj dawb tso hmoov thiab ethyl cawv. Qhov no kuaj txoj kev.

3. Kev npaj ntawm electrolytic chloroform (hluav taws xob tam sim no) rau alkali hlau chlorides nyob rau hauv cov cua ntawm acetone los yog ethyl cawv. Tsis tas li ntawd ib tug kuaj txoj kev ua trichloromethane.

tu

Tom qab chloroform yog tau txais, nws yuav tsum tau ntxuav. Tom qab tag nrho, yog hais tias nws yog siv rau kev kho mob hom phiaj, cov ntsiab lus ntawm impurities nyob rau hauv nws yog tsuas tsis tsim nyog. Yog hais tias lub hom phiaj hauv daim ntawv thov specifications, cov ntsiab lus ntawm txawv teb chaws tshuaj yuav tsum tau txwv.

Tej zaum yuav muaj ntau yam impurities uas muaj chloroform. Yuav ua li cas yog nws? Yuav ua li cas yog lawv?

• Ethyl cawv.
• Hydrogen chloride.
• Phosgene.
• Cov tshuaj chlorine ua.

Muaj ob txoj kev uas mus ntxuav cov impurities ntawm chloroform:

• copious muab yaug nrog dej raws li los ntawm qhuav (pub rau kiag li tau tshem ntawm ethanol);
• trichloromethane ntxuav nrog muaj zog acid, ces nrog ib tug muaj zog alkali, ua raws li los ntawm cov dej. Tom ntej kev kho mob yog qhuav los ntawm kev siv ib tug dehydrating neeg sawv cev - calcium chloride. Cov khoom no ces fractionally distilled rau ib kem.

Keeb kwm ntawm foundations

Txij thaum yog lub npe hu rau chloroform? Yuav ua li cas yog nws thiab dab tsi yog nws siv ua ntej? Sim kom to taub.

Tus thawj mention ntawm no substance thov rau xyoo 1831. Thaum ntawd yog thaum ib tug chemist los ntawm Guthrie Chaw nres nkoj twb tau txais trichloromethane. Txawm li cas los, lub hom phiaj ntawm nws tsis yog tus yeeb tshuaj, nws yog qhov zoo tshaj plaws by-product. Lub chemist kuj nrhiav kuab tshuaj rau roj hmab, experimented thiab ntawd tau txais chloroform.

Nyob rau hauv tib lub xyoo, thiab ib xyoos tom qab ntawd lwm ob zaum ntawm nws tus kheej tau ua los ntawm thwmsim no substance. Nws Yustas Libih (uas ua ib tug zoo pab rau txoj kev loj hlob ntawm Science News for KIDS) thiab Eugen Subereyn. Lawv ua hauj lwm yog mus nrhiav ib tug ua kom loog, thiab lawv pom nws. Txawm li cas los, peb pom tawm txog qhov no nyhuv ntawm chloroform thiab pib siv nws tom qab, tsuas muaj lub 1840s.

Cov yam ntxwv mis thiab cov kev sis raug zoo ntawm atoms nyob rau hauv lub molecule kawm thiab tswj tsim chemist Dumas nyob rau hauv 1834 xyoo. Nws npaj siab thiab nyab xeeb rau cov chloroform nws lub npe, uas tau muab nyob rau hauv Honor ntawm tus ntsaum. Nyob rau hauv Latin ntsaum pronounced formiata, raws li muaj nyob rau hauv cov kab formic acid yog tau tsim los ntawm chloroform. Nyob rau qhov no hauv paus, thiab qhia hais tias yuav nws lub npe.

Lub lom ntxim rau cov tib neeg

Nws justifies nws siv li ib tug ua kom loog chloroform. Nyhuv rau cov neeg yog heev txog, yuav tsum vov ob peb loj hloov khoom nruab nrog nruab.

Lub degree ntawm lub hwj nyob rau yam tseem ceeb xws li:

• concentration nqus tau cov pa tshuaj;
• lub caij ntawm kev siv;
• txoj kev hauv tsev.

Thaum nws los txog rau ntshiab, kev kho mob chloroform, ces nws siv yog nruj me ntsis dosed meej thiab Senior. Yog li ntawd, tau contraindications siv xwb ob peb tug. Yog hais tias peb yuav sib tham txog lub chloroform qhuav nyob rau hauv cov huab cua thiab nqus tau cov pa ib feem ntawm nws cov neeg, qhov kev txiav txim no yog ntau npaum li cas loj thiab puas.

Yog li, nqus tau pa ntawm trichloromethane thaum lub sij hawm 10 feeb yuav tshwm sim caj pas edema, pulmonary spasm, hnoos, mob caj pas. Yog hais tias tej yam tsis nres lub lom tshwm sim tam sim ntawd. Nws yuav tsum ntaus los ntawm lub paj hlwb (thiab lub taub hau thiab tus txha caj qaum), tejzaum tuag taus.

Tsis tas li ntawd nyhuv dejnum rau hauv lub siab, ob lub raum thiab digestive kabmob muaj chloroform. Nws cov nyhuv yog tshwj xeeb tshaj yog ua yog coj mus tov. Cai nram qab no tus kab mob tus tshuaj tiv thaiv rau lub txais tos ntawm chloroform:

• kiv taub hau;
• ntuav thiab xeev siab;
• pheej mob taub hau;
• central lub paj hlwb kev nyuaj siab thiab raws li ib tug tshwm sim, qaug zog;
• kub taub hau;
• tsis haum ua pob ua xyua, daim tawv nqaij liab.

Kev tshawb fawb thiab thwmsim rau ntau yam tsiaj tau qhia cov nram qab no tshwm sim:

1. Long-term siv chloroform rau hauv ib lub kua ua kev cuam tshuam uas cev xeeb tub, ntau yam pathology thiab mutagenesis ntawm yav tom ntej tiam.
2. Thaum lub atmospheric lub neej ntawm chloroform tsiaj twb nyuaj siab, sluggish thiab lub caij ntawm lawv lub neej yog significantly txo.
3. Raws li thwmsim nrog nas, nws twb xaus lus carcinogenicity trichloromethane.

Cov kev tshwm sim twb tau chemists thiab cov kws kho mob nyob rau hauv txoj kev tshawb no los ntawm cov uas muaj sia nyob ntawm chloroform.

Siv nyob rau hauv cov tshuaj

Tus thawj mention ntawm kev kho mob siv ntawm lub yam khoom uas yog rooted nyob rau hauv lub xyoo 1847. Nws yog ces hais tias ib tus paub txog, ib tug kws kho mob, ib tug chemist Holmes Coote thawj npaj rau kev siv ntawm chloroform li ib tug ua kom loog. Nyhuv rau cov neeg nws muaj nyob rau hauv lub lag luam lub sij hawm zoo - ib tug ua tiav shutdown nco qab, cov uas tsis muaj lwm txoj kev.

Tab sis tom qab ntawd, thaum tus neeg mob regained nco qab, nws twb qhia hais tias nws tsis tau kev tso xeev siab, ntuav. Ces twb tau tsim ntau leej cai ntawm daim ntawv thov ntawm cov tshuaj yeeb dej caw kom tsis txhob zoo li no yuav tshwm.

Ib tug heev ib qho tseem ceeb luag hauj lwm nyob rau hauv cov kev taw qhia rau cov tshuaj chloroform ua si English obstetrician Dzheyms Simpson. Nws yog nws leej twg muaj pov thawj zoo nyhuv ntawm tus compound thiab thaum lub sij hawm yug me nyuam txheej txheem.

Txawm li cas los, muaj ntau tshiab, kev nyab xeeb thiab kev niaj hnub ua kom loog dua chloroform lub sij hawm. Nws siv nyob rau hauv cov tshuaj yog xyaum zoo. Niaj hnub no, nws yog siv nyob rau hauv daim ntawv ntawm:

• tivthaiv tshuaj pleev rau lwm daim ntawv thov;
• raws li ib tug extension ntawm kev ua kom loog nyob rau hauv ua ke nrog nrog rau lwm cov tshuaj, thiab tsuas yog nyob rau heev uas tsis muaj ntau;
• raws li dauv relieving xeev siab thiab ntuav.

muaj daim ntaub ntawv

Cov kev lag luam kuj siv chloroform. Nws daim ntawv thov koom rau ntau yam tshuaj syntheses, qhov twg nws plays lub luag hauj lwm ntawm kuab degreaser, thawj los sis theem nrab tivthaiv rau cov tseem ceeb tshuaj siv nyob rau hauv tag nrho cov cheeb tsam ntawm kev tib neeg kev ua si.