Carbide: formula, application thiab properties

Ntau qhov sib txawv ntawm cov tshuaj lom neeg muaj lub npe nyob hauv lub ntiaj teb: txog pua pua lab. Thiab tag nrho cov ntawm lawv, zoo li tib neeg, yog tib neeg. Koj tuaj yeem nrhiav ob hom tshuaj uas muaj tib yam tshuaj lom neeg thiab lub cev ua rau sib txawv.

Ib qho ntawm feem ntau nthuav cov duab uas muaj nyob hauv lub ntiaj teb yog cov carbides. Nyob rau hauv tsab xov xwm no, peb yuav tham txog lawv cov qauv, lub cev thiab cov khoom siv tshuaj, thov thiab tshawb xyuas cov ntsiab lus ntawm lawv cov khoom. Tab sis ua ntej, me ntsis txog keeb kwm ntawm foundations.

Keeb kwm

Hlau carbides, cov qauv uas peb yuav muab rau hauv qab no, tsis yog sib txuas lus teb. Qhov no yog vim muaj qhov tseeb tias lawv cov molecules yuav tawg ua kom sib thooj nrog dej. Yog li, ntawm no nws yog tsim nyog tham txog cov thawj cov kev sim coj los ua ke.

Txij li thaum 1849, muaj cov neeg ua tim khawv rau lub pob zeb ntawm silicon carbide, tab sis qee cov kev sim no tseem tshuav qhov tsis muaj tseeb. Ntau qhov kev tsim tau pib xyoo 1893 los ntawm American chemist Edward Acheson nyob rau hauv ib txoj kev uas tom qab lub npe hu ua nws.

Lub keeb kwm ntawm cov synthesis ntawm calcium carbide kuj tsis txawv. Xyoo 1862, nws tau txais ib tug kws kho mob German, Friedrich Wöhler, cua sov zinc thiab calcium uas muaj roj.

Tam sim no wb txav mus rau ntau qhov chaw tshwj xeeb: tshuaj lom neeg thiab lub cev. Tom qab tag nrho, lawv yog cov essence ntawm daim ntawv thov ntawm chav kawm ntawm cov tshuaj.

Lub cev lub cev

Kiag tag nrho cov carbides txawv nyob rau hauv lawv cov hardness. Piv txwv li, ib tug ntawm cov khib nyiab nyob rau hauv lub Mohs scale yog tungsten carbide (9 tawm ntawm 10 tau cov ntsiab lus). Tsis tas li ntawd, cov tshuaj yeeb dej caw no zoo heev: lub nruab deg ntawm qee qhov ntawm lawv nce mus txog ob txhiab degrees.

Feem ntau cov carbides sib txig sib luag thiab sib cuam tshuam nrog me me ntawm cov tshuaj yeeb dej caw. Lawv tsis yog daws teeb meem nyob rau hauv tej lub kuab tshuaj. Txawm li cas los xij, txoj kev sib dej nrog dej yuav raug suav tias yog kev sib yeem, nrog kev rhuav tshem cov nyiaj thiab cov tsim ntawm lub hydroxide ntawm cov hlau thiab cov roj carbon.

Qhov kawg cov tshuaj tiv thaiv thiab ntau lwm yam tshuaj lom neeg hloov kev txuam nrog carbides yuav muab los tham hauv tshooj txuas mus ntxiv.

Tshuaj lom neeg

Yuav luag tag nrho cov carbides dej nrog dej. Ib txhia - yooj yim thiab tsis muaj cua sov (piv txwv li, calcium carbide), thiab ib co (e.g., Karbid Kremniya) - pa dej thaum rhuab mus 1800 degrees. Reactivity nyob rau hauv cov ntaub ntawv no yog nyob ntawm seb qhov nyiaj ntawm cov nyiaj hauv lub compound, uas peb yuav tham txog tom qab. Nyob hauv cov tshuaj tiv thaiv dej, muaj ntau hom kev hlav hydrocarbon. Qhov no tshwm sim vim tias cov dej muaj nyob hauv dej yog nyob nrog cov pa roj carbon dioxide. Yuav kom nkag siab tias hom roj carbon dioxide tau zoo li cas (los yog ob qho tib si lub limiting thiab lub unsaturated compound tau txais), ib tug muaj peev xwm pib ua los ntawm lub siab ntawm cov pa roj carbon uas muaj nyob hauv thawj cov khoom. Piv txwv li, yog hais tias peb muaj ib tug calcium carbide, uas nws mis yog CAC _2, peb pom hais tias nws muaj cov C ₂ ^2- ion. Qhov no txhais tau hais tias ob lub hom phom rau hydrogen nrog rau tus nqi them * tuaj yeem txuas nrog nws. Yog li, peb muab tau cov compound C ₂ H ₂ - acetylene. Nyob rau hauv tib txoj kev los ntawm ib tug compound xws li txhuas carbide, uas nws mis Al ₄ C _3, peb ch _4. Yog vim li cas tsis C ₃ H _12, koj hais? Tom qab tag nrho, cov ion muaj ib tug nqi ntawm 12-. Qhov tseeb yog qhov tsawg kawg ntawm cov xaim hluav taws xob atoms yog txiav txim siab los ntawm formula 2n + 2, qhov twg n yog pes tsawg tus carbon atoms. Li no, tsuas yog ib tug compound ntawm cov mis C ₃ H ₈ (hluav taws roj zeb) tej zaum yuav muaj raws li tus ion nrog xwb 12 kev uas yuav ntog mus rau hauv peb ion nrog xwb 4, uas tsim, thaum ua ke nrog protons methane molecule.

Nthuav yog qhov tshuaj oxidation ntawm cov carbides. Lawv tuaj yeem tshwm sim los ntawm kev sib zog ua ke ntawm oxidants, thiab nyob rau hauv qhov hluav taws xob hauv nruab nrab hauv cov pa oxygen. Yog tias muaj pa oxygen txhua yam meej: ob oxides yog tau, ces nrog rau lwm cov oxidizers nws yog qhov kev nthuav ntau dua. Txhua yam nyob ntawm qhov xwm txheej ntawm cov hlau uas yog ib feem ntawm lub carbide, thiab tseem nyob ntawm qhov chaw ntawm oxidant. Piv txwv li, Karbid Kremniya, uas nws mis sic, los ntawm reacting nrog ib tug sib tov ntawm nitric thiab hydrofluoric acids, ntaub ntawv hexafluorosilicic acid nrog carbon dioxide. Thiab thaum lub sij hawm tib cov tshuaj tiv thaiv, tiam sis nrog tsuas yog ib qho nitric acid, peb tau ib tug silicon oxide thiab carbon dioxide. Oxidizers kuj muaj xws li halogens thiab chalcogenes. Nrog lawv, txhua yam kev sib tw ua ke, cov qauv tshuaj no tsuas yog nyob ntawm nws cov qauv xwb.

Hlau carbides, cov qauv uas peb tau pom, yog tsis yog txhais tias tsuas yog cov neeg sawv cev ntawm cov chav kawm ntawm cov sib txuas. Tam sim no peb yuav ua tib zoo saib ntawm txhua qhov tseem ceeb ntawm cov chav kawm hauv chav kawm no thiab tham txog lawv daim ntawv thov nyob rau hauv peb lub neej.

Dab tsi yog cov carbides?

Nws hloov tawm, carbide, uas nws mis yog, piv txwv li, CAC _2, raws ho nyob rau hauv cov qauv los ntawm sic. Thiab qhov txawv yog feem ntau nyob rau ntawm qhov ntawm daim ntawv cog lus ntawm lub atoms. Nyob rau hauv rooj plaub thawj zaug, peb tabtom soj ntsuam nrog lub ntsev xws li ntsev. Cov chav kawm ntawm cov tebchaw no muaj npe vim yog nws coj qhov tseeb li ntsev, uas yog, nws muaj peev xwm sawv tawm tsam rau hauv ions. Xws li ib qho ionic daim ntawv cog lus yog qaug zog heev, uas ua rau nws yooj yim mus nqa tawm lub qhov ua kom haj yam muaj zog thiab lwm yam kev hloov txuam nrog kev sib tshuam ntawm ions.

Lwm, tej zaum kuj yog qhov tseem ceeb ntawm carbide industrially cov covalent carbides: xws li, piv txwv li, SiC lossis WC. Lawv yog cov yam ntxwv siab thiab lub zog. Zoo li tsis muaj zog thiab siv zog los txo cov tshuaj.

Tseem muaj cov hlau zoo li cov carbides. Lawv tuaj yeem xav tau tias yog cov hlau sib xyaw hlau nrog carbon. Cov no yuav qhia tau, e.g., cementite (hlau carbide, uas nws mis yuav ua tau txawv, tab sis nws yog kwv yees li qhov nruab nrab: Fe ₃ C), los yog hlau. Lawv muaj tshuaj lom neeg ua haujlwm, nrab nyob rau hauv nws cov degree ntawm ionic thiab covalent carbides.

Txhua yam ntawm cov subspecies ntawm cov chav kawm ntawm cov tshuaj lom neeg sib txuas peb tau tawm tswv yim muaj nws cov ntawv thov. Txog li cas thiab txhua qhov ntawm lawv thov, peb mam li tham hauv tshooj ntxiv.

Cov ntaub ntawv siv ntawm carbides

Raws li peb twb tau sib tham lawm, cov ntawv carbides muaj ntau ntau yam kev siv cov tswv yim. Cov no suav nrog cov khoom siv thiab cov khoom txiav, thiab cov ntaub ntawv sib xyaw uas siv rau ntau yam kev lag luam (piv txwv li, ib yam ntawm cov ntaub ntawv muaj nyob rau hauv lub cev muaj tej cuab yeej), thiab cov khoom siv, hluav taws xob, cua sov, thiab nuclear zog. Thiab qhov no tsis yog txhua daim ntawv teev cov npe ntawm cov kab lus no.

Qhov siv qis tshaj plaws yog ua los ntawm ntsev-tsim cov carbides. Cov tshuaj tiv thaiv dej ua siv los ua ib txoj kev sim rau kev muab cov roj carbon monoxide. Yuav ua li cas qhov no tshwm sim, peb twb tau rhuav tshem saum toj no.

Nrog rau cov ntawv cog lus, cov hlau zoo li cov carbides muaj daim ntaub ntawv siv rau kev lag luam. Raws li peb tau hais lawm hais tias, zoo li cov hlau zoo li tej lub tebchaw uas peb sib tham yog cov hlau, cast iron thiab lwm yam kev sib txuas ntawm cov hlau nrog cov impregnations. Raws li txoj cai, cov hlau muaj nyob rau hauv tej yam tshuaj muaj npe rau chav kawm ntawm d-hlau. Tias yog vim li cas nws yog inclined rau daim ntawv tsis bondage, tab sis raws li nws tau mus rau hauv tus qauv ntawm cov hlau.

Nyob rau hauv peb lub tswv yim, muaj ntau tshaj li cov tswv yim uas siv rau cov kev cai saum toj no. Tam sim no cia saib qhov txheej txheem ntawm lawv.

Ntau ntawm carbides

Thawj ob hom carbides uas peb tau xav txog, uas yog cov kua zaub thiab ntsev, zoo li feem ntau tau ua ib txoj hauv kev yooj yim: los ntawm cov tshuaj oxid thiab coke thaum kub siab. Nyob rau tib lub sijhawm, ib feem ntawm qhov coke uas muaj cov pa roj carbon atom yog sib xyaw nrog lub caij atom hauv oxide thiab cov ntaub ntawv carbide. Lwm qhov "yuav siv" oxygen thiab cov ntawv carbon monoxide. Qhov no yog qhov muaj zog heev-rau siab, vim nws yuav tsum tswj kev kub siab (li 1600-2500 degrees) hauv cheeb tsam tshuaj tiv thaiv.

Yuav kom tau qee lub hom kev sib txuas, kev siv lwm tus yog siv. Piv txwv, kev hloov ntawm lub compound, uas nws thiaj li muab cov carbide. Cov mis nyuj tov yog nyob ntawm qhov cov paj xyeem, ces peb yuav tsis tham txog nws.

Ua ntej ua tiav peb lub tshooj, peb yuav tham txog qee qhov kev saib xyuas zoo thiab tham txog lawv hauv ntau yam.

Interesting sib txuas

Sodium carbide. Cov mis ntawm lub compound C ₂ Na _2. Qhov no tuaj yeem sawv cev tam li acetylide (uas yog, qhov khoom hloov chaw hloov roj carbon atom hauv acetylene rau sodium atoms), thiab tsis yog carbide. Cov mis nyuj tov mis tsis muaj kev cuam tshuam txog cov khoom siv no, yog li ntawd lawv yuav tsum tau nrhiav hauv tus qauv. Nws yog ib qho ua haujlwm heev thiab, thaum sib txuas nrog dej, cuam tshuam nrog nws kom muaj acetylene thiab alkali.

Magnesium carbide. Formula: MgC _2. Txoj kev ntawm qhov no txaus nyiam lub cev yog nthuav. Ib tug ntawm lawv pom sintering ntawm magnesium fluoride nrog calcium carbide ntawm kev kub. Yog li ntawd, ob yam khoom tau: Calcium fluoride thiab cov carbide peb xav tau. Cov mis rau cov tshuaj tiv thaiv no yooj yim heev, thiab koj tuaj yeem ua tau, yog tias koj xav tau, nyeem cov ntawv tshwj xeeb.

Yog tias koj tsis paub meej txog cov khoom siv ntawm cov khoom hauv tsab xov xwm, ces tom ntej no yog rau koj.

Qhov no yuav pab tau li cas hauv lub neej?

Zoo, thawj zaug, kev paub ntawm cov tshuaj chiv muaj peev xwm yeej tsis ua tau ntau dua. Nws yog ib txwm zoo dua los ua kev txawj ntse nrog kev txawj ntse kom nyob tsis muaj nws. Secondly, qhov ntau koj paub txog cov hav zoov ntawm cov tebchaw, qhov zoo dua koj nkag siab txog lub tswv yim ntawm lawv cov tsim thiab cov cai uas cia lawv nyob ua ib ke.

Ua ntej yuav mus xaus, kuv xav muab qee cov kev pom zoo rau txoj kev kawm txog cov khoom siv no.

Yuav ua li cas los kawm qhov no?

Nws yooj yim heev. Qhov no tsuas yog ib feem ntawm Chemistry. Thiab nws yuav tsum tau kawm raws li cov phau ntawv nyeem ntawm Chemistry. Pib nrog tsev kawm ntawv cov ntaub ntawv thiab nkag mus rau hauv ntau dua, los ntawm cov phau ntawv kawm university thiab cov phau ntawv siv.

Xaus

Lub ntsiab lus no tsis yog yooj yim thiab tho txawv li nws zoo li thaum xub thawj siab. Chemistry yeej ib txwm ua tau yog tias koj pom koj lub hom phiaj rau hauv.