Cov thawj thiab thib ob txoj cai ntawm Faraday

Lub ntsha yeej ib txwm muaj ib qhov nqi ntawm ions nrog tej yam tshwm sim "plus" thiab "rho tawm", npaj los ntawm reacting lub lwg me me ntawm yaj tshuaj nrog lub kuab. Thaum nws tshwm sim nyob rau hauv ib tug hluav taws xob field, ions pib tsiv mus nyob rau lub electrodes, qhov zoo maj mus rau lub cathode, tsis zoo - mus rau lub anode. Tom qab ncav qhov electrodes, lub ions muab rau lawv cov nqi yog hloov dua siab tshiab rau hauv nruab nrab atoms thiab tso rau hauv lub electrodes. Qhov ntau haum ions mus rau lub electrodes, ntau dua qhov yuav muab ncua tau cov tshuaj.

Qhov no yog tus xyuas peb thiaj li paub tuaj empirically. Dua ib tug tam sim no los ntawm cov aqueous tov ntawm tooj liab sulfate , thiab yuav soj ntsuam qhov kev tso tawm ntawm tooj liab rau cov pa roj carbon cathode. Peb nrhiav tau hais tias nws yog thawj them nrog ib tug txheej ntawm tooj liab NW nyuam qhuav hnov, ces raws li qhov tam sim no bandwidth yuav ua rau kom nws, thiab los ntawm heev tso cai ntawm lub tam sim no yog muaj nyob rau ntawm lub carbon electrode loj thickness txheej ntawm tooj liab, uas yog ib qho yooj yim mus lo, piv txwv li, tooj liab hlau.

Cov tshwm sim ntawm kev rho tawm cov ntaub ntawv uas nyob rau hauv lub electrodes thaum tam sim no dhau los ntawm lub ntsha yog hu ua electrolysis.

Dhau los ntawm ntau yam sib txawv electrolysis currents thiab ua tib zoo ntsuas lub loj ntawm ib yam khoom tso rau ntawm lub electrodes ntawm txhua tus ntawm cov ntsha, cov kawm lus Askiv physicist Faraday nyob rau hauv 1833 - 1834 xyoo. Kuv qhib ob Law rau electrolysis.

Tus thawj Faraday txoj cai tsim kev sib raug zoo ntawm cov loj ntawm ib yam khoom uas dim los ntawm electrolysis thiab tus nqi nqi uas tau dhau los ntawm lub ntsha.

Qhov no txoj cai yog formulated raws li nram no: loj ntawm ib yam khoom uas tau sau ua ke thaum lub sij hawm electrolysis, nyob rau txhua electrode yog ncaj qha proportional rau tus nqi ntawm them nyiaj uas tau dhau los ntawm lub ntsha:

m = kq,

qhov twg m - loj ntawm cov khoom uas tau raug rho tawm, q - xwb.

Tus nqi k - elektrohimicheskimy sib npaug substance. Nws yog raug rau txhua yam khoom uas tso tawm thaum lub sij hawm lub ntsha.

Yog hais tias koj noj cov mis q = 1 pendant, ces k = m, piv txwv li electrochemical sib npaug ntawm tus tshuaj yuav tsum tau txaus sib npaug zos rau tus luj ntawm tshuaj xaiv los ntawm cov ntsha los dua ib tug xwb nyob rau hauv ib tug pendant.

Qhia nyob rau hauv cov mis mos ntawm tus nqi tam sim no kuv thiab lub sij hawm t, peb tau:

m = cov khoom siv.

Cov thawj txoj kev cai Faraday soj ntsuam rau cov kev raws li nram no. Dua ib tug tam sim no los ntawm cov electrolytes A, B thiab C. Yog hais tias lawv yeej zoo tib yam, ces tus loj ntawm lub substance nyob rau hauv lub A, B thiab C yuav tau kho raws li lub currents kuv, I1, I2. Cov nab npawb ntawm cov tshuaj xaiv nyob rau hauv A, yog sib npaug zos rau cov sum ntawm cov tagnrho faib rau B thiab C, txij thaum lub tam sim no kuv = I1 + I2.

Qhov thib ob Faraday txoj cai tsim lub dependence ntawm lub electrochemical sib npaug ntawm atomic nyhav thiab valence tshuaj thiab formulated raws li nram no: electrochemical sib npaug ntawm tus tshuaj yuav proportional rau lawv atomic hnyav, thiab inversely xwm yeem mus rau nws valency.

Qhov ratio ntawm cov atomic luj ntawm lub substance rau nws valence hu ua tshuaj sib npaug substance. Nkag mus rau cov nqi no, qhov thib ob Faraday txoj cai yuav tsum formulated txawv: cov electrochemical sib npaug ntawm tus tshuaj yog proportional rau lawv tus kheej cov tshuaj kom muaj sib npaug.

Cia Electrochemical kom muaj sib npaug ntawm txawv tshuaj yog feem k1 thiab K2, yog cov K3, ..., KN, tshuaj tib kom muaj sib npaug ntawm tib yam x1 thiab x2, x23, ..., xn, ces k1 / K2 = x1 / x2, los yog k1 / x1 = K2 / x2 = K3 / x 3 = ... = KN / xn.

Nyob rau hauv lwm yam lus, qhov ratio ntawm cov electrochemical sib npaug ntawm tus tshuaj rau tus nqi ntawm lub tib lub substance yog ib qhov rau tag nrho cov tshuaj muaj tib lub nqi:

k / x = c.

Nws hais ntxiv hais tias tus piv ntawm k / x yog qhov rau tag nrho cov tshuaj:

k / x = c = 0, 01036 (meq) / k.

Tus nqi qhia rau yuav ua li cas muaj ntau yam milligram kom muaj sib npaug tshuaj rau cov electrodes yog tso tawm thaum lub sij hawm cov zaj ntawm lub ntsha ntawm hluav taws xob xwb, sib npaug zos rau 1 coulomb. Qhov thib ob txoj cai ntawm Faraday sawv cev los ntawm cov mis:

k = cx.

Pauv qhov no qhia rau k nyob rau hauv thawj txoj kev cai Faraday, ob yuav ua ke rau hauv ib qhia:

m = kq = cxq = cxIt,

qhov twg c - universal qhov ntawm 0 00001036 (eq) / k.

Qhov no qhia tau hais tias mis los ntawm xeem dhau tus tib tam sim no rau tib lub sij hawm ntawm lub sij hawm nyob rau hauv ob tug sib txawv ntsha, peb cais tawm ob lub kom muaj nuj nqis ntawm tshuaj electrolytes hais txog raws li cov tshuaj kom muaj sib npaug thereof.

Txij li thaum x = A / n, ces peb yuav tau sau:

m = CA / qe ntshauv,

i.e., qhov loj ntawm ib yam khoom uas xaiv nyob rau hauv lub electrodes thaum lub sij hawm electrolysis yuav ncaj qha proportional rau nws atomic luj, tam sim no, sij hawm, thiab inversely xwm yeem mus rau valency.

Qhov thib ob txoj cai ntawm Faraday rau electrolysis, raws li zoo raws li cov thawj, li nram no ncaj qha los ntawm qhov xwm ntawm tus ion tam sim no nyob rau hauv cov tshuaj.

Faraday txoj cai, Lenz, raws li zoo li ntau lwm mas physicists ua si ib tug lossis loj lub luag hauj lwm nyob rau hauv lub keeb kwm thiab kev loj hlob ntawm physics.