Electrolytes raws li tshuaj tau paub txij thaum ub. Txawm li cas los xij, lawv tau kov yeej feem ntau ntawm lawv thaj chaw ntawm daim ntawv thov tsis ntev los no. Peb yuav sib tham txog qhov tseem ceeb tshaj plaws rau kev lag luam siv cov tshuaj no thiab txheeb xyuas seb qhov tom kawg yog dab tsi thiab lawv txawv ntawm ib leeg. Tab sis cia peb pib nrog kev tsis ncaj ncees rau hauv keeb kwm.
History
Cov laus tshaj plaws paub electrolytes yog ntsev thiab kua qaub nrhiav tau nyob rau hauv lub ntiaj teb ancient. Txawm li cas los xij, cov tswv yim hais txog cov qauv thiab cov khoom ntawm electrolytes tau hloov zuj zus mus rau lub sijhawm. Cov kev xav ntawm cov txheej txheem no tau hloov zuj zus txij li xyoo 1880s, thaum muaj ntau qhov kev tshawb pom tau hais txog kev xav ntawm cov khoom ntawm electrolytes. Muaj ntau qhov kev hloov pauv zoo hauv kev xav piav qhia txog cov txheej txheem ntawm kev cuam tshuam ntawm electrolytes nrog dej (tom qab tag nrho, tsuas yog hauv kev daws lawv tau txais cov khoom vim lawv siv hauv kev lag luam).
Tam sim no peb yuav txheeb xyuas ntau yam kev xav uas tau muaj kev cuam tshuam loj tshaj plaws ntawm kev tsim cov tswv yim txog electrolytes thiab lawv cov khoom. Thiab cia peb pib nrog txoj kev xav uas feem ntau thiab yooj yim uas peb txhua tus tau coj hauv tsev kawm.
Arrhenius Theory of Electrolytic Dissociation
xyoo 1887Swedish chemist Svante Arrhenius thiab Lavxias-German chemist Wilhelm Ostwald tsim txoj kev xav ntawm electrolytic dissociation. Txawm li cas los xij, txhua yam tsis yooj yim ntawm no ib yam nkaus. Arrhenius nws tus kheej yog tus txhawb nqa ntawm qhov kev xav ntawm lub cev ntawm kev daws teeb meem, uas tsis suav nrog kev sib cuam tshuam ntawm cov khoom sib xyaw nrog dej thiab sib cav tias muaj cov khoom siv dawb (ions) hauv cov tshuaj. Los ntawm txoj kev, nws yog los ntawm cov haujlwm zoo li no uas electrolytic dissociation tau txiav txim siab hauv tsev kawm hnub no.
Cia peb tham txog qhov kev xav no muab thiab nws piav qhia rau peb txog kev sib cuam tshuam ntawm cov tshuaj nrog dej li cas. Zoo li txhua tus neeg, nws muaj ob peb lub ntsiab lus uas nws siv:
1. Thaum sib cuam tshuam nrog dej, cov khoom decomposes rau hauv ions (zoo - cation thiab negative - anion). Cov khoom no tau txais kev ywg dej: lawv nyiam cov dej molecules, uas, los ntawm txoj kev, raug them zoo ntawm ib sab thiab tsis zoo them rau lwm yam (tsim dipole), vim li ntawd, lawv tsim rau hauv aqua complexes (solvates).
2. Cov txheej txheem ntawm dissociation yog thim rov qab - uas yog, yog tias cov khoom tau tawg mus rau hauv ions, tom qab ntawd nyob rau hauv kev cuam tshuam ntawm txhua yam nws tuaj yeem tig mus rau qhov qub.
3. Yog tias koj txuas cov electrodes rau kev daws teeb meem thiab pib tam sim no, ces cov cations yuav pib txav mus rau qhov tsis zoo electrode - cathode, thiab cov anions ntawm qhov zoo them - lub anode. Tias yog vim li cas cov khoom uas muaj cov dej soluble heev hauv dej ua hluav taws xob zoo dua li dej nws tus kheej. Lawv kuj tseem hu ua electrolytes rau tib lub laj thawj.
4. Lub degree ntawm dissociation ntawm cov electrolyte characterizes feem pua ntawm cov khoom uas tau undergone dissolution. Qhov noqhov taw qhia nyob ntawm cov khoom ntawm cov kuab tshuaj thiab cov kuab tshuaj nws tus kheej, ntawm qhov concentration ntawm tom kawg thiab nyob rau sab nraud kub.
Ntawm no, qhov tseeb, thiab tag nrho cov ntsiab lus ntawm qhov kev xav yooj yim no. Peb yuav siv lawv hauv kab lus no los piav qhia txog dab tsi tshwm sim hauv cov tshuaj electrolyte. Peb yuav txheeb xyuas cov piv txwv ntawm cov tebchaw me ntsis tom qab, tab sis tam sim no peb yuav xav txog lwm txoj kev xav.
Lewis txoj kev xav ntawm acids thiab bases
Raws li txoj kev xav ntawm electrolytic dissociation, ib qho kua qaub yog ib yam khoom uas muaj hydrogen cation tam sim no, thiab lub hauv paus yog ib qho sib xyaw uas decomposes rau hauv hydroxide anion hauv kev daws. Muaj lwm txoj kev xav muaj npe tom qab tus kws kho mob nto moo Gilbert Lewis. Nws tso cai rau koj mus rau me ntsis nthuav lub tswvyim ntawm acid thiab puag. Raws li Lewis txoj kev xav, cov kua qaub yog ions lossis cov khoom siv ntawm cov khoom uas muaj cov hluav taws xob dawb dawb thiab muaj peev xwm txais tau ib qho hluav taws xob los ntawm lwm cov molecule. Nws yog ib qho yooj yim rau kwv yees tias cov hauv paus yuav yog cov khoom zoo li no uas tuaj yeem pub ib lossis ntau dua ntawm lawv cov electrons rau "siv" ntawm cov kua qaub. Nws yog qhov nthuav heev ntawm no uas tsis yog tsuas yog electrolyte xwb, tab sis kuj tseem muaj cov khoom, txawm tias insoluble hauv dej, tuaj yeem yog cov kua qaub lossis cov hauv paus.
Brandsted-Lowry protolithic theory
Nyob rau xyoo 1923, ob tug kws tshawb fawb - J. Bronsted thiab T. Lowry - tau thov ib txoj kev xav uas tam sim no siv los ntawm cov kws tshawb fawb los piav txog cov txheej txheem tshuaj. Lub ntsiab ntawm qhov kev xav no yog qhov ntawddissociation yog txo mus rau kev hloov ntawm ib tug proton los ntawm ib tug acid mus rau lub hauv paus. Yog li, tom kawg tau nkag siab ntawm no ua tus txais proton. Ces cov kua qaub yog lawv pub. Txoj kev tshawb xav kuj piav qhia txog qhov muaj nyob ntawm cov khoom uas nthuav tawm cov khoom ntawm ob qho tib si acids thiab bases. Xws li cov tebchaw hu ua amphoteric. Hauv Bronsted-Lowry txoj kev xav, lub sij hawm ampholytes kuj tseem siv rau lawv, thaum acids lossis bases feem ntau hu ua protoliths.
Peb tau los rau ntu tom ntej ntawm tsab xov xwm. Ntawm no peb yuav qhia koj tias qhov muaj zog thiab tsis muaj zog electrolytes txawv ntawm ib leeg thiab sib tham txog kev cuam tshuam ntawm lwm yam ntawm lawv cov khoom. Thiab tom qab ntawd peb yuav pib piav qhia lawv cov kev siv tau.
Muaj zog thiab tsis muaj zog electrolytes
Txhua yam khoom cuam tshuam nrog dej ib tus zuj zus. Ib txhia yaj zoo nyob rau hauv nws (piv txwv li, lub rooj ntsev), thaum ib txhia tsis yaj kiag li (piv txwv li, chalk). Yog li, txhua yam khoom raug muab faib ua cov muaj zog thiab tsis muaj zog electrolytes. Cov tom kawg yog cov khoom uas cuam tshuam tsis zoo nrog dej thiab nyob hauv qab ntawm cov tshuaj. Qhov no txhais tau hais tias lawv muaj kev sib cais tsawg heev thiab muaj kev sib raug zoo siab zog, uas nyob rau hauv ib txwm mob tsis tso cai rau cov molecule decompose rau hauv nws cov ions. Lub dissociation ntawm qaug zog electrolytes tshwm sim los yog qeeb heev, los yog nrog ib tug nce nyob rau hauv kub thiab concentration ntawm cov tshuaj no nyob rau hauv kev daws.
Cia tham txog cov electrolytes muaj zog. Cov no suav nrog tag nrho cov ntsev soluble, nrog rau cov acids muaj zog thiab alkalis. Lawv yooj yim tawg mus rau hauv ions thiab nws nyuaj heev los sau lawv hauv nag lossis daus. Tam sim no hauv electrolytes, los ntawm txoj kev, yog uaprecisely vim cov ions muaj nyob rau hauv cov tshuaj. Yog li ntawd, muaj zog electrolytes ua tam sim no zoo tshaj plaws ntawm tag nrho cov. Piv txwv ntawm tom kawg: muaj zog acids, alkalis, soluble ntsev.
Yam cuam tshuam rau tus cwj pwm ntawm electrolytes
Tam sim no cia peb txheeb xyuas seb qhov kev hloov pauv hauv ib puag ncig sab nraud cuam tshuam li cas ntawm cov khoom. Cov concentration ncaj qha cuam tshuam rau qib ntawm electrolyte dissociation. Ntxiv mus, qhov piv txwv no tuaj yeem nthuav qhia lej. Txoj cai piav txog txoj kev sib raug zoo no yog hu ua Ostwald dilution law thiab sau raws li nram no: a=(K / c)1/2. Ntawm no yog qhov degree ntawm dissociation (kub nyob rau hauv feem), K yog qhov dissociation tas li, uas txawv rau txhua yam khoom, thiab c yog qhov concentration ntawm cov electrolyte nyob rau hauv cov tshuaj. Los ntawm cov qauv no, koj tuaj yeem kawm ntau yam txog cov khoom thiab nws tus cwj pwm hauv kev daws teeb meem.
Tab sis peb digress. Ntxiv rau qhov concentration, qhov degree ntawm dissociation kuj cuam tshuam los ntawm qhov kub ntawm electrolyte. Rau feem ntau cov tshuaj, nws nce solubility thiab reactivity. Qhov no tuaj yeem piav qhia txog qhov tshwm sim ntawm qee qhov kev tshwm sim tsuas yog nyob rau qhov kub siab. Raws li ib txwm muaj, lawv mus qeeb heev, lossis hauv ob qho kev qhia (cov txheej txheem zoo li no hu ua thim rov qab).
Peb tau txheeb xyuas cov xwm txheej uas txiav txim siab tus cwj pwm ntawm lub cev xws li cov tshuaj electrolyte. Tam sim no cia peb mus rau qhov kev siv ntawm cov no, tsis muaj kev poob siab, tshuaj tseem ceeb heev.
siv kev lag luam
Tau kawg, txhua tus tau hnov lo lus "electrolyte"muaj feem xyuam rau cov roj teeb. Lub tsheb siv cov roj teeb lead-acid, cov electrolyte uas yog 40% sulfuric acid. Yuav kom nkag siab tias yog vim li cas cov tshuaj no xav tau nyob rau hauv tag nrho, nws tsim nyog nkag siab txog cov yam ntxwv ntawm cov roj teeb.
Yog li lub hauv paus ntsiab lus ntawm lub roj teeb yog dab tsi? Nyob rau hauv lawv, ib tug reversible cov tshuaj tiv thaiv ntawm transformation ntawm ib yam khoom mus rau lwm yam tshwm sim, raws li ib tug tshwm sim ntawm cov electrons raug tso tawm. Thaum lub roj teeb raug them, kev sib cuam tshuam ntawm cov tshuaj yuav tshwm sim, uas tsis tau txais nyob rau hauv ib txwm muaj. Qhov no tuaj yeem sawv cev raws li qhov sib xyaw ntawm hluav taws xob hauv cov khoom siv los ntawm cov tshuaj tiv thaiv tshuaj. Thaum qhov tso tawm pib, qhov rov qab hloov pauv pib, ua rau lub cev mus rau thawj lub xeev. Ob txheej txheem no ua ke ua ib lub voj voog uas them nqi.
Cia peb xav txog cov txheej txheem saum toj no ntawm ib qho piv txwv tshwj xeeb - roj teeb txhuas-acid. Raws li koj tuaj yeem twv, qhov chaw tam sim no muaj cov khoom siv lead ua (nrog rau cov hlau lead dioxide PbO2) thiab acid. Txhua lub roj teeb muaj cov khoom siv hluav taws xob thiab qhov chaw nruab nrab ntawm lawv, tsuas yog ntim nrog electrolyte. Raws li qhov kawg, raws li peb tau pom lawm, hauv peb qhov piv txwv, sulfuric acid yog siv los ntawm 40 feem pua. Lub cathode ntawm lub roj teeb no yog ua los ntawm cov hlau lead dioxide, thiab cov anode yog ua los ntawm cov hlau lead ntshiab. Tag nrho cov no yog vim qhov txawv txav rov qab tshwm sim ntawm ob lub electrodes nrog kev koom tes ntawm ions rau hauv cov kua qaub dissociated:
- PbO2 + SO42-+ 4H+ + 2e-=PbSO4 + 2H2O(kev tshwm sim tshwm sim ntawm qhov tsis zoo electrode - cathode).
- Pb + SO42- - 2e-=PbSO 4 (Reaction ntawm qhov zoo electrode - anode).
Yog tias peb nyeem cov kev cuam tshuam los ntawm sab laug mus rau sab xis - peb tau txais cov txheej txheem uas tshwm sim thaum lub roj teeb tawm, thiab yog los ntawm sab xis mus rau sab laug - thaum them nyiaj. Hauv txhua qhov tshuaj tam sim no, cov tshuaj tiv thaiv no txawv, tab sis cov txheej txheem ntawm lawv qhov tshwm sim feem ntau tau piav qhia nyob rau hauv tib txoj kev: ob txheej txheem tshwm sim, nyob rau hauv ib qho ntawm cov electrons yog "absorbed", thiab lwm yam, ntawm qhov tsis sib xws, lawv " tawm". Qhov tseem ceeb tshaj plaws yog tus naj npawb ntawm absorbed electrons yog sib npaug rau tus naj npawb ntawm emitted ones.
Qhov tseeb, ntxiv rau cov roj teeb, muaj ntau yam kev siv ntawm cov tshuaj no. Feem ntau, electrolytes, piv txwv ntawm peb tau muab, tsuas yog ib qho nplej ntawm ntau yam tshuaj uas tau ua ke hauv lub sijhawm no. Lawv nyob ib puag ncig peb, txhua qhov chaw. Piv txwv li, piv txwv li, tib neeg lub cev. Koj puas xav tias cov tshuaj no tsis nyob ntawd? Koj yuam kev heev. Lawv nyob txhua qhov chaw hauv peb, thiab qhov loj tshaj plaws yog cov ntshav electrolytes. Cov no suav nrog, piv txwv li, hlau ions, uas yog ib feem ntawm hemoglobin thiab pab thauj oxygen mus rau cov ntaub so ntswg ntawm peb lub cev. Cov ntshav electrolytes tseem ua lub luag haujlwm tseem ceeb hauv kev tswj cov dej-ntsev tshuav thiab lub plawv ua haujlwm. Qhov kev ua haujlwm no yog ua los ntawm cov poov tshuaj thiab sodium ions (tseem muaj cov txheej txheem uas tshwm sim hauv cov hlwb, uas yog hu ua lub twj tso kua mis potassium-sodium).
Txhua yam khoom uas koj tuaj yeem yaj txawm tias me ntsis yog electrolytes. Thiab tsis muaj kev lag luam thiab peb lub neej nrog koj, qhov twgtxawm lawv siv los xij. Qhov no tsis yog tsuas yog cov roj teeb hauv tsheb thiab cov roj teeb. Qhov no yog txhua yam tshuaj thiab khoom noj khoom haus, cov nroj tsuag tub rog, khaub ncaws factories thiab lwm yam.
Cov khoom xyaw ntawm cov electrolyte, los ntawm txoj kev, txawv. Yog li, nws muaj peev xwm paub qhov txawv acidic thiab alkaline electrolyte. Lawv sib txawv hauv lawv cov khoom: raws li peb tau hais lawm, acids yog cov neeg pub dawb, thiab alkalis yog cov neeg txais. Tab sis dhau sij hawm, muaj pes tsawg leeg ntawm cov electrolyte hloov vim qhov poob ntawm ib feem ntawm cov khoom, qhov concentration yog txo los yog nce (nws tag nrho yog nyob ntawm qhov ploj, dej los yog electrolyte).
Peb ntsib lawv txhua hnub, tab sis ob peb tus neeg paub meej lub ntsiab lus ntawm cov lus xws li electrolytes. Peb tau npog cov piv txwv ntawm cov khoom tshwj xeeb, yog li cia peb mus rau me ntsis ntxiv cov ntsiab lus.
Lub cev muaj zog ntawm electrolytes
Tam sim no hais txog physics. Qhov tseem ceeb tshaj plaws kom nkag siab thaum kawm cov ncauj lus no yog li cas tam sim no kis hauv electrolytes. Ions ua lub luag haujlwm txiav txim siab hauv qhov no. Cov khoom uas raug them no tuaj yeem hloov cov nqi ntawm ib feem ntawm cov tshuaj mus rau lwm qhov. Yog li, anions ib txwm nyiam rau qhov zoo electrode, thiab cations - mus rau qhov tsis zoo. Yog li, ua raws li kev daws teeb meem nrog hluav taws xob tam sim no, peb cais cov nqi sib txawv ntawm cov kab ke.
nthuav heev yog lub cev zoo li qhov ntom. Ntau yam khoom ntawm cov tebchaw peb tab tom tham nyob ntawm nws. Thiab cov lus nug feem ntau tshwm sim: "Yuav ua li cas nce qhov ntom ntawm electrolyte?" Qhov tseeb, cov lus teb yog yooj yim: koj yuav tsum tau downgrade cov ntsiab lusdej hauv kev daws. Txij li qhov ceev ntawm cov electrolyte feem ntau txiav txim siab los ntawm qhov ntom ntawm sulfuric acid, nws feem ntau nyob ntawm qhov concentration ntawm cov tom kawg. Muaj ob txoj hauv kev los ua kom tiav txoj kev npaj. Thawj qhov yooj yim heev: boil cov electrolyte uas muaj nyob rau hauv lub roj teeb. Ua li no, koj yuav tsum tau them nws kom qhov kub thiab txias hauv qhov nce me ntsis siab dua ib puas degrees Celsius. Yog tias txoj kev no tsis pab, tsis txhob txhawj, muaj lwm qhov: tsuas yog hloov cov electrolyte qub nrog ib qho tshiab. Txhawm rau ua qhov no, ntws cov kua dej qub, ntxuav cov sab hauv ntawm sulfuric acid residues nrog dej distilled, thiab tom qab ntawd ncuav rau hauv ib qho tshiab. Raws li txoj cai, cov kev daws teeb meem zoo electrolyte tam sim ntawd muaj qhov xav tau concentration. Tom qab hloov pauv, koj tuaj yeem hnov qab ntev ntev txog yuav ua li cas txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm
Cov khoom xyaw ntawm cov electrolyte feem ntau txiav txim siab nws cov khoom. Cov yam ntxwv xws li hluav taws xob conductivity thiab ntom, piv txwv li, yog nyob ntawm qhov zoo ntawm cov kuab tshuaj thiab nws cov concentration. Muaj ib lo lus nug cais txog pes tsawg electrolyte tuaj yeem nyob hauv lub roj teeb. Qhov tseeb, nws qhov ntim yog ncaj qha ntsig txog lub zog tshaj tawm ntawm cov khoom. Qhov ntau sulfuric acid nyob rau hauv lub roj teeb, lub zog ntau dua, piv txwv li, qhov voltage ntau nws tuaj yeem tsim.
Nws tuaj nyob qhov twg?
Yog tias koj yog tus nyiam tsheb lossis tsuas yog mus rau hauv tsheb, ces koj tus kheej nkag siab txhua yam. Muaj tseeb koj txawm paub yuav ua li cas txiav txim siab npaum li cas electrolyte nyob rau hauv lub roj teeb tam sim no. Thiab yog tias koj nyob deb ntawm tsheb, ces kev paubCov khoom ntawm cov tshuaj no, lawv cov kev siv thiab yuav ua li cas lawv cuam tshuam nrog ib leeg yuav tsis yog superfluous kiag li. Paub qhov no, koj yuav tsis poob yog tias koj raug nug kom hais tias electrolyte nyob rau hauv lub roj teeb. Txawm hais tias txawm tias koj tsis yog tus neeg nyiam tsheb, tab sis koj muaj lub tsheb, ces paub txog cov cuab yeej roj teeb yuav tsis yog superfluous thiab yuav pab koj kho. Nws yuav yooj yim dua thiab pheej yig dua ua txhua yam koj tus kheej dua li mus rau qhov chaw pib.
Thiab txhawm rau kom kawm tau zoo dua cov ncauj lus no, peb xav kom nyeem phau ntawv qhia txog tshuaj lom neeg rau cov tsev kawm ntawv thiab tsev kawm qib siab. Yog tias koj paub qhov kev tshawb fawb no zoo thiab tau nyeem cov ntawv nyeem txaus, Varypaev's "Chemical Current Sources" yuav yog qhov kev xaiv zoo tshaj. Nws piav qhia meej txog tag nrho txoj kev xav ntawm kev ua haujlwm ntawm cov roj teeb, ntau lub roj teeb thiab hydrogen cells.
Zoo kawg
Peb los txog kawg. Cia peb sau tseg. Saum toj no, peb tau txheeb xyuas txhua yam ntsig txog lub tswv yim xws li electrolytes: piv txwv, kev xav ntawm cov qauv thiab cov khoom, kev ua haujlwm thiab kev siv. Ib zaug ntxiv nws tsim nyog hais tias cov tebchaw no yog ib feem ntawm peb lub neej, tsis muaj peb lub cev thiab txhua qhov chaw ntawm kev lag luam yuav tsis muaj nyob. Koj puas nco qab cov ntshav electrolytes? Ua tsaug rau lawv peb nyob. Yuav ua li cas txog peb lub tsheb? Nrog rau qhov kev paub no, peb yuav tuaj yeem kho txhua qhov teeb meem ntsig txog lub roj teeb, raws li tam sim no peb nkag siab tias yuav ua li cas txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm
Nws tsis tuaj yeem hais txhua yam, thiab peb tsis tau teem lub hom phiaj zoo li no. Tom qab tag nrho, qhov no tsis yog txhua yam uas tuaj yeem hais txog cov tshuaj zoo kawg no.
