Yuav ua li cas yog electrolysis? Lub anode thiab cathode. Physico-tshuaj txheej txheem

Rau ib ntev lub sij hawm cov neeg tsis tswj kom tau ib tug ntau ntawm cov ntshiab tshuaj nyob rau hauv lub dawb daim ntawv. Xws li rau Piv txwv li:

• co;
• alkalis;
• chloro;
• hydrogen;
• hydrogen peroxide;
• organic tshuaj thiab lwm tus neeg.

Lawv tau txais ib theem siab cov ntsiab ntawm impurities, los ntawm uas nws yog tsis yooj yim sua kom tshem tau ntawm, los yog tsis tsim rau tag nrho cov. Tab sis kev twb kev txuas yog qho tseem ceeb heev rau kev siv nyob rau hauv kev lag luam thiab lub neej txhua hnub. Tiam sis nrog lub foundations ntawm ib tug txheej txheem xws li electrolysis, ib tug neeg ua hauj lwm ntawm enormous proportions tau lawm. Niaj hnub no nws yog siv tsis tsuas yog rau cov synthesis, tab sis kuj rau ntau ntau lwm yam dab.

Yuav ua li cas yog electrolysis? Raws li nws tshwm sim, ib txhia ntawm cov theem piled, dab tsi yog qhov tseem ceeb kom zoo dua ntawm no txoj kev, ua kom to taub cov chav kawm ntawm lub tsab xov xwm.

Yuav ua li cas yog electrolysis?

Yuav kom teb tau lo lus nug no, peb yuav tsum xub nrhiav kom to taub cov terminology thiab ib co yooj yim lub cev thiab tshuaj ntsiab lus.

1. DC - ib tug qhia kwj ntawm cov electrons originating los ntawm txhua qhov chaw los ntawm hluav taws xob.
2. Ntsha - yeeb tshuaj, tshuaj uas muaj peev xwm sawv ntawm txoj kev hluav taws xob tam sim no.
3. Electrodes - phaj ntawm tej ntaub ntawv, interconnected, uas dhau hluav taws xob los ntawm lawv tus kheej (anode thiab cathode).
4. Lub redox cov tshuaj tiv thaiv - ib tug txheej txheem nyob rau hauv uas muaj ib tug kev hloov nyob rau hauv lub degree ntawm oxidation ntawm cov neeg koom. Hais tias yog, ib co ions oxidize thiab ua rau kom tus nqi ntawm cov degree ntawm oxidation, thaum lwm tus uas txo, tej nws.

Thaum clarified tag nrho cov nqe lus, koj yuav tau teb cov lus nug ntawm yog dab tsi electrolysis. Qhov no redox txheej txheem, muaj dua ib tug tib neeg tam sim no los ntawm cov ntsha tov thiab yog haujlwm los ntawm qhov kev tso tawm ntawm txawv cov khoom nyob rau hauv lub electrodes.

Ib qho yooj yim installation, uas muaj peev xwm yuav hu ua electrolyzer, yuav tsuas ib tug ob peb lub Cheebtsam:

• ob tsom iav nrog ib tug ntsha;
• ib tug tam sim no qhov twg los;
• ob electrodes yog interconnected.

Cov kev lag luam siv ib tug ntau npaum li cas complex caw kaw lus tsim, uas tau loj tus xov tooj ntawm cov khoom - electrolysis da.

electrolysis txheej txheem yog haum complex, yog raug mus rau ob peb theoretical kev cai thiab tau nyaij raws li qhov kev txiav txim thiab kev cai. Yuav kom raug twv seb lub sij hawm, tag nrho cov kev cai thiab tau zaj yuav tsum tau kawm tau zoo.

Lub theoretical cov me nyuam yaus ntawm tus txheej txheem

Qhov tseem ceeb tshaj yuav tsum muaj canons uas rests electrolysis - cov kev cai ntawm Michael Faraday - tus naas ej physicist, lub npe hu rau nws ua hauj lwm nyob rau hauv lub teb ntawm hluav taws xob tam sim no thiab tag nrho cov nrog dab.

Tag nrho tej kev cai ob, txhua tus uas qhia txog cov essence ntawm cov txheej txheem nyob rau hauv lub electrolysis.

Cov thawj txoj kev cai

Tus thawj txoj cai ntawm Faraday, cov mis uas yog sau raws li m = Ki * Δt, yog raws li nram no.

Pawg tshuaj tawm ntawm lub electrode yog ncaj qha proportional rau hluav taws xob, uas tau dhau los ntawm lub ntsha.

Cov mis qhia tau hais tias tus m - yog qhov loj ntawm cov khoom, I - tam sim no siv, Δt - lub sij hawm thaum lub sij hawm uas nws yog dhau lawm. Tseem tau sau yog tus nqi ntawm k, uas yog hu ua tus electrochemical sib npaug ntawm tus compound. Qhov no tus nqi nyob ntawm qhov xwm ntawm tus compound nws tus kheej. K yog txaus sib npaug zos rau qhov loj ntawm lub tshuaj uas yog tso tawm nyob rau electrode los ntawm cov ntsha thaum dua ib chav tsev ntawm hluav taws xob xwb.

Qhov thib ob txoj cai ntawm electrolysis

Qhov thib ob txoj cai ntawm Faraday, cov mis uas - m = M * Kuv * Δt / n * F, yog raws li nram no. Ib electrochemical sib npaug ntawm tus compound (k) yog ncaj qha proportional rau nws hniav puas loj, thiab inversely xwm yeem mus rau valence ntawm lub substance.

Qhov saum toj no mis yog lub txiaj ntsim ntawm tus ntsoos ntsoos ntawm tag nrho cov teb chaws. Nws captures lub essence ntawm lub thib ob txoj cai ntawm electrolysis. M - hniav puas loj tebchaw, kuv - tam sim no siv dhau rau tag nrho cov txheej txheem, Δt - tag nrho electrolysis lub sij hawm, F - Faraday tus tsis tu ncua, n - electrons uas muab kev koom tes nyob rau hauv tus txheej txheem. Lawv tus xov tooj yog sib npaug zos rau hauv them nyiaj ntawm lub ion, coj ib feem nyob rau hauv tus txheej txheem.

Faraday tus kev cai uas pab to taub dab tsi yog electrolysis, thiab xam lub peev xwm tawm los los ntawm qhov hnyav, qhov xav no yog twv seb thiab feem xyuam rau txoj kev kawm ntawm tus txheej txheem. Lawv tshwm sim tawm lub theoretical lub hauv paus ntawm lub transformations.

Lub tswvyim ntawm tus anode thiab nws cov hom

Heev tseem ceeb nyob rau hauv lub electrolysis electrodes. Tag nrho cov txheej txheem yog nyob rau hauv cov ntaub ntawv los ntawm qhov uas lawv ua, lawv kev xwm thiab zog. Yog li ntawd, peb xav txog nyob rau hauv ntau yam txhua ntawm lawv.

Anode - ntxiv los yog zoo electrode. Uas yog, yog ib tug uas yog txuas mus rau lub "+" ncej ntawm lub hwj chim qhov twg los. Raws li, rau nws los ntawm lub ntsha tov yuav tsiv mus nyob tsis zoo ions los yog anions. Lawv yuav oxidize no, nkag mus rau hauv ib tug ntau dua degree ntawm oxidation.

Yog li ntawd, peb yuav kos ib tug me ntsis daim duab uas yuav pab tau nco ntsoov anodic dab: ib tug anode "plus" - anions - oxidation. Yog li muaj ob theem pib hom ntawm tus electrode, nyob ntawm seb uas yuav tig ib qho khoom.

1. Lub insoluble los yog inert anode. Tej yam xws li ib tug electrode uas ua hauj lwm pab xwb mus rau cov hloov electrons thiab oxidation dab, tiam sis nws yog tsis noj thiab tsis yaj. Tej anodes yog ua los ntawm graphite, iridium, platinum, carbon thiab thiaj li nyob. Siv cov electrodes, lub co yuav tau ua nyob hauv cov ntshiab gases (oxygen, hydrogen, tshuaj chlorine ua thiab thiaj li nyob).
2. Lub soluble anode. Thaum oxidative dab nws yaj thiab muaj feem xyuam rau lub sij hawm ntawm lub electrolysis. Cov yooj yim ntaub ntawv ntawm kev tsim kho rau no hom ntawm electrode: npib tsib xee, tooj liab, cadmium, hmoov txhuas, tin, zinc thiab lwm tus neeg. Siv cov anodes xav tau rau electrorefining kev ntawm hlau, electroplating, kev tiv thaiv txheej tiv thaiv xeb, thiab hais txog.

Lub essence ntawm cov txheej txheem uas tshwm sim nyob rau hauv qhov zoo electrode yog txo mus rau tawm feem ntau electronegative ions tiag tej zaum. Ivot vim li cas anions hydrogen acids thiab hydroxide ion, thiab ces tus dej, yog hais tias nws yog ib tug tshuaj. Pa-muaj anions nyob rau hauv ib tug aqueous ntsha tov, feem ntau nyob rau hauv lub anode yog tsis pom, txij thaum lub dej ua rau nws ceev, tso oxygen.

Lub cathode thiab nws tus yam ntxwv

Lub cathode - yog ib tug zoo them electrode (vim tsub zuj zuj ntawm electrons rau nws thaum ib tug hluav taws xob tam sim no). Uas yog vim li cas rau nws tsiv zoo them ions - cations uas niaj kev ncaj ncees, uas yog, txo cov neeg kawm ntawv ntawm oxidation.

Muaj kuj yog tsim nyog yuav tau nco ntsoov tswvyim cathode "rho tawm" - ntawv - rov qab. Raws li cov khoom siv rau lub cathode muaj xws li:

• stainless steel;
• tooj liab;
• carbon;
• toog;
• hlau;
• txhuas thiab lwm tus neeg.

Nws yog nyob rau no electrode los rau co rov qab los ntawm ntshiab tshuaj, uas yog ib tug ntawm lub ntsiab txoj kev ua lawv industrially. Nws tseem yog tau cov kev hloov ntawm electrons los ntawm cov anode mus rau lub cathode, thiab yog hais tias tus thawj - soluble, nws ions yog txo rau qhov tsis zoo electrode. Ntawm no yog ib tug kho tshiab ntawm cations rau hydrogen gas H _2. Yog li ntawd, lub cathode - yog ib tug ntawm cov tseem ceeb tshaj plaws qhov chaw nyob rau hauv lub zuag qhia tag nrho tswvyim ntawm electrolysis ntawm tshuaj.

electrolysis ntawm melts

Los ntawm qhov seem yus pom ntawm tshuaj txoj kev nyob rau hauv saib xyuas nws muaj nws kab zauv. Nrog nws tau los sawv cev rau tag nrho cov Circuit Court rau ntawm daim ntawv thiab twv seb lub sij hawm. Qhov tseem ceeb tshaj plaws uas koj yuav tsum xyuam xim rau - cov muaj los yog tsis tuaj kawm ntawv ntawm cov dej ib puag ncig thiab lub hom ntawm cov anode (soluble los yog tsis).

Yog hais tias tsim nyog los muab cov nram qab no cov khoom: alkali thiab alkaline ntiaj teb co, alkalis, txhuas, beryllium, anions ntawm cov pa uas muaj gases yuav tsis tau ces yuav ib lo lus nug txog lub electrolysis ntawm lub ntsha tov. Cia li yaj, vim hais tias tsis yuav tsum tau sib txuas yuav tsis ua hauj lwm. Uas yog vim li cas nyob rau hauv lub lag luam feem ntau coj los ua ke cov tshuaj, siv lawv qhuav anhydrous ntsev thiab hydroxides.

Nyob rau hauv kev, yaj electrolysis kab zauv yooj yim heev thiab txheem. Piv txwv li, yog hais tias peb xav txog thiab sau nws rau poov tshuaj iodide, tus saib yuav tau cov nram no:

Ki = K ^{+ +} kuv ^-

Lub cathode (K) "-" K ⁺ K + 1 e = ⁰

Lub anode ^{(A) "+": 2I - -} 2e = kuv ₂ ⁰

Txheej txheem Tau: Ki = K + kuv _2.

Ib yam li ntawd, electrolysis yuav sau tej hlau tsis hais nws electrode peev xwm.

Electrolysis ntawm lub aqueous tov

Thaum nws los txog rau ntsha kev daws teeb meem, lub sij hawm ntawm tus txheej txheem yuav tsum tau txawv heev. Tom qab tag nrho, dej yog ua ib tug active neeg. Nws tseem yog muaj peev xwm sawv ntawm dissociating rau hauv ions thiab tawm los ntawm cov electrodes. Yog li ntawd, nyob rau hauv xws li mob ib qho tseem ceeb electrode tej zaum ions. Tshaj tsis zoo nqi yog tsawg dua, qhov ntau dua qhov yuav ntawm ntau sai oxidation los yog yuav txo.

Electrolysis ntawm lub aqueous tov yog kev kawm mus rau ob peb cov kev cai uas yuav tsum tau cim.

1. Anodic dab: tawm xwb anions ntawm hydrogen acids (tsuas yog hydrogen fluoride). Yog hais tias ib tug oxygen ion los yog fluoride ion, ces dej yuav tsum oxidized rau tso pa.
2. Lub cathodic dab: electrowinning co nyob rau hauv lub electrochemical series (mus txog rau thiab inclusive ntawm txhuas) nyob rau hauv cathode tsis tau rov qab los vim lub high tshuaj ua si. Qhov no ua rau cov dej rau tso hydrogen. Co los ntawm txhuas rau hydrogen rov qab los ib txhij nrog dej mus yooj yim tshuaj. Cov uas yog tom qab hydrogen nyob rau hauv lub electrochemical series (uas tsis muaj kev ua si), nkag yauv txo rau yooj yim tshuaj.

Yog hais tias koj ua raws li cov cai no, peb yuav qhia tej electrolysis thiab xam tau tawm los. Nyob rau hauv cov ntaub ntawv ntawm ib tug soluble anode Circuit Court mas nws txawv thiab yuav ntau npaum li cas complicated.

electrolysis ntsev

Cov dab yog siv rau cov uas muab ntshiab co thiab gases, vim nws yog technologically yooj yooj yim thiab kev lag kev luam zoo. Nyob rau hauv tas li ntawd, cov khoom tuaj nrog ib tug high degree ntawm kev coj dawb huv, uas yog ib qho tseem ceeb.

Piv txwv li, electrowinning ntawm tooj liab yuav sai sai tau nws nyob hauv cov ntshiab daim ntawv los ntawm ib tug tov ntawm tej ntsev. Cov feem ntau siv tooj liab sulfate los yog tooj liab sulfate (II) - CuSO _4.

Raws li ib tug yaj los yog tshuaj ntawm lub ntsev yuav tau muab rho tawm ntshiab hlau, uas yog li ntawd tsim nyog nyob rau hauv txhua lub sectors ntawm Hluav taws xob thiab hlau engineering.

Lub ntsiab lus thiab daim ntawv thov txheej txheem

Electrolysis - ib tug tseem ceeb heev txoj kev. Thaum nws puag yog raws li yog tus tsim nyog kev ua hauj lwm, xws li:

1. hlau refining.
2. Electroextraction.
3. Electroplating.
4. Electrosynthesis.
5. Daim ntawv thov ntawm anti-xeb coatings thiab lwm tus neeg.