Likarabelo tsa Lik'hemik'hale Liseleng tsa Electrolytic
Sele ea electrolytic ke sesebelisoa se sebelisang matla a motlakase ho qobella karabelo ea lik'hemik'hale eo hangata e neng e ke ke ea etsahala ka tšohanyetso. Ho fapana le lisele tsa galvanic (lisele tsa voltaic), tse hlahisang motlakase ho tsoa liketsong tsa redox tse sa reroang, lisele tsa electrolytic li "ja" motlakase ho fetola lintho hore e be mefuta e meng ka mekhoa ea oxidation le phokotso. Theknoloji ena e bohlokoa indastering ea sejoale-joale, ho tloha ho plating ea tšepe le ho hloekisa koporo ho ea tlhahisong ea khase ea haedrojene le oksijene le tlhahiso ea aluminium. Karolo ea mantlha ea sele ea electrolytic e lik'hemik'haleng tsa eona: phetoho e laoloang ea lintho ka motlakase.
Mehopolo ea Motheo: Likarabelo tsa Redox le Motsamao oa Elektrone
Bohlokwa ba electrolysis ke karabelo ya redox (reduction-oxidation). Oxidation ke ho lokollwa ha dielektrone, ha phokotso e le keketseho ya dielektrone. Seleng ya electrolytic, mohlodi wa motlakase o kantle o qobella dielektrone ho phalla ka hara potoloho, e leng se dumellang karabelo ya redox ho etsahala hodima dielektrode.
Ho na le li-electrode tse peli tse ka sehloohong: anode le cathode. Seleng ea electrolytic, anode ke electrode moo ho etsahalang oxidation, ha cathode e le electrode moo ho bang le phokotso. Sena hangata sea ferekanya hobane liseleng tsa galvanic matšoao a litefiso tsa electrode a fapane, empa litlhaloso tsa oxidation ho anode le phokotso ho cathode li lula li tšoana bakeng sa lisele tsohle tsa electrochemical.
Electrolyte ke sebui se tsamaisang motlakase ka motsamao oa li-ion. Li-electrolyte e ka ba litharollo tsa letsoai, li-acid, li-base, kapa metsoako ea ionic e qhibilihisitsoeng. Ha motlakase o phalla, li-cation (li-ion tse chajileng hantle) li fallela ho cathode ho ea fokotseha, ha li-anion (li-ion tse chajileng hampe) li fallela ho anode ho ea oxidation. Kahoo, ntle le phallo ea li-electron potolohong e ka ntle, ho na le phallo ea li-ion ka har'a electrolyte ho boloka tekanyo ea tjhaja.
Likarolo tsa Sele ea Electrolytic le Mesebetsi ea Tsona
Ka kakaretso, sele ea electrolytic e na le:
1. Phepelo ea motlakase: e fana ka phapang e ka bang teng e le hore likarabelo tse sa reroang li ka etsahala.
2. Li-electrode tse peli: e ka ba li-electrode tse sa sebetseng (mohlala, graphite kapa platinum) kapa li-electrode tse sebetsang (mohlala, koporo ho hloekisoeng ha koporo).
3. Li-electrolyte: lintho tse etsang hore motlakase o be matla e le hore li ka tsamaisa motlakase.
4. Lijana le lipotoloho: boloka sistimi e tsitsitse 'me e lumella ho shebella lihlahisoa tsa karabelo.
Khetho ea electrode le electrolyte e etsa qeto e kholo ea mofuta oa karabelo e hlahang. Mohlala, electrode e sa sebetseng ha e kenelle karabelong ka mokhoa o sa fetoheng, ha electrode e sebetsang e ka qhibiliha kapa ea potlaka e le karolo ea karabelo.
Likarabelo tsa Lik'hemik'hale ho Cathode: Mokhoa oa ho Fokotsa
Ho cathode, phokotso e etsahala, ho bolelang hore mofuta oa lik'hemik'hale o fumana lielektrone. Litharollong tsa metsi, bakhethoa ba phokotso hangata ke li-cation tsa tšepe kapa limolek'hule tsa metsi (kapa li-ion tsa haedrojene). Karabelo e hlahang e itšetlehile ka mekhoa ea phokotso ea mofuta ka mong.
Mehlala e tloaelehileng:
1. Phokotso ea li-ion tsa tšepe
Mohlala, electrolysis ea tharollo ea CuSO₄ ka li-electrode tse sa sebetseng:
\[
\mongolo{Cu}^{2+} + 2e^- \motsu \mongolo{Cu(s)}
\]
Li-ion tsa Cu²⁺ li amohela lielektrone 'me li fetoha koporo e tiileng ho cathode.
2. Phokotso ea metsi e hlahisa haeterojene
Litharollong moo ho leng thata ho fokotsa li-cation (mohlala, Na⁺ kapa K⁺ ka metsing), metsi a fokotseha habonolo:
\[
2\mongolo{H}_2\mongolo{O} + 2e^- \motsu o nepahetseng \mongolo{H}_2(g) + 2\mongolo{OH}^-
\]
Ka lebaka leo, khase ea haedrojene e thehoa ka har'a cathode, 'me tharollo e potolohileng cathode e ba ea motheo haholoanyane ka lebaka la ho thehoa ha OH⁻.
Ka hona, ho cathode, ho ka hlaha tshepe kapa ho thehwa ha kgase, ho itshetlehile ka maemo a sistimi.
Likarabelo tsa Lik'hemik'hale ho Anode: Ts'ebetso ea Oxidation
Ho anode, ho hlaha oxidation, e leng ho lokolloa ha dielektrone. Mefuta e ka oxidation hangata ke di-anion (tse kang Cl⁻, Br⁻) kapa metsi (a hlahisang O₂). Jwalo ka ho cathode, dihlahiswa ho anode di itshetlehile ka mofuta wa ion le bonolo ba oxidation.
Mehlala e tloaelehileng:
1. Ho qhibilihisoa ha li-ion tsa chloride ho hlahisa chlorine
Ka electrolysis ea tharollo e matla ea NaCl (brine), anion ea Cl⁻ e ka oxidized:
\[
2\mongolo{Cl}^- \motsu o nepahetseng \mongolo{Cl}_2(g) + 2e^-
\]
Khase ea chlorine e thehoa ho anode.
2. Ho ntsha oksijene metsing ho hlahisa oksijene
Haeba anion e le thata ho e oxidation (mohlala, SO₄²⁻ kapa NO₃⁻), metsi a tla oxidation:
\[
2\mongolo{H}_2\mongolo{O} \motsu o nepahetseng \mongolo{O}_2(g) + 4\mongolo{H}^+ + 4e^-
\]
Khase ea oksijene e thehoa ho anode, 'me tharollo e potileng anode e ba le asiti e ngata ka lebaka la ho thehoa ha H⁺.
Qeto ea "seo se nang le oxidized" ho anode hangata e khethoa ke mahloriso a li-ion, mofuta oa electrode, le maemo a ts'ebetso (voltage, pH, le overpotential).
Mohlala oa Bohlokoa oa Nyeoe: Electrolysis ea Metsi
Ho qhibilihisa metsi ka motlakase ke mohlala o motle o bontshang karabelo ho di-electrode ka bobedi. Ha e le hantle, metsi a hlwekileng ke mokganni o fokolang haholo wa motlakase, kahoo electrolyte (mohlala, H₂SO₄ e hlapollotsweng kapa KOH) hangata e eketswa ho eketsa mokganni.
Karabelo ho cathode:
\[
2\mongolo{H}_2\mongolo{O} + 2e^- \motsu o nepahetseng \mongolo{H}_2(g) + 2\mongolo{OH}^-
\]
Karabelo ho anode:
\[
2\mongolo{H}_2\mongolo{O} \motsu o nepahetseng \mongolo{O}_2(g) + 4\mongolo{H}^+ + 4e^-
\]
Haeba dielektrone di leka-lekane mme di kopantswe, karabelo yohle ke:
\[
2\mongolo{H}_2\mongolo{O(l)} \motsu o nepahetseng 2\mongolo{H}_2(g) + \mongolo{O}_2(g)
\]
Ho tsoa karabelong ena ho ka bonoa hore metsi a bola ho ba haeterojene le khase ea oksijene ka karolelano ea bophahamo ba 2:1, ho latela stoichiometry ea equation ea karabelo.
Electrolysis ea Tharollo ea NaCl: Tlhahiso ea Chlorine le Sodium Hydroxide
Indastering, e 'ngoe ea lits'ebetso tsa bohlokoa ka ho fetisisa tsa electrolysis ke electrolysis ea litharollo tse matla tsa NaCl tse sebelisang lisele tsa membrane kapa diaphragm. Likarabelo tse hlahang ke:
Cathode:
\[
2\mongolo{H}_2\mongolo{O} + 2e^- \motsu o nepahetseng \mongolo{H}_2(g) + 2\mongolo{OH}^-
\]
Anode:
\[
2\mongolo{Cl}^- \motsu o nepahetseng \mongolo{Cl}_2(g) + 2e^-
\]
Karabelo eohle:
\[
2\text{NaCl(aq)} + 2\text{H}_2\text{O(l)} \rightarrow \text{Cl}_2(g) + \text{H}_2(g) + 2\text{NaOH(aq)}
\]
Liphetho li bohlokoa haholo: chlorine bakeng sa indasteri ea lik'hemik'hale, haeterojene e le mafura kapa thepa e tala, le NaOH bakeng sa sesepa, pampiri le mekhoa e fapaneng ea ho hloekisa.
Molao oa Faraday: Kamano Pakeng tsa Tefiso ea Motlakase le Bongata ba Lintho
Likarabelo tsa lik'hemik'hale ka seleng ea electrolytic li amana haufi-ufi le bongata ba tjhaja ea motlakase e phallang. Molao oa Faraday o re boima ba ntho e entsoeng kapa e bolileng ho electrode bo lekana le bongata ba tjhaja ea motlakase (Q) e fetang.
Tefiso ea motlakase:
\[
Q = Ke \makhetlo t
\]
ka I ea hona joale (ampere) le t nako (metsotsoana). Palo ea li-mole tsa lielektrone:
\[
n(e^-) = \frac{Q}{F}
\]
moo F e leng ntho e sa fetoheng ya Faraday (≈ 96485 C/mol electrons). Ho tloha ho sena, re ka bala boima ba tshepe e kentsweng kapa bophahamo ba kgase bo hlahiswang ho latela stoichiometry ya karabelo ya electrode. Ke ka lebaka lena electrolysis e leng molemo hakaale: dihlahiswa di ka bolelwa esale pele le ho laolwa ka nepo.
Mabaka a Amang Likarabelo tsa Electrolysis
Mabaka a mang a ka sehloohong a susumetsang liketso tsa lik'hemik'hale liseleng tsa electrolytic ke:
1. Mofuta oa ion ka har'a electrolyte: o khetholla mofuta o ka fokotsoang/o nang le oxidized.
2. Ho bokellana ha li-ion: li-ion tse ngata tse kopaneng hangata li ameha habonolo liketsong.
3. Thepa ea li-electrode: li-electrode tse sa sebetseng khahlanong le tse sebetsang li ka hlahisa lihlahisoa tse fapaneng.
4. Motlakase le hona joale: fumana sekhahla sa karabelo le monyetla oa likarabelo tse ka thoko.
5. pH le mocheso: li ama tekano le kinetics ea karabelo.
Ho laola lintlha tsena ho bohlokoa hore ts'ebetso ea electrolysis e sebetse hantle 'me e hlahise lihlahisoa tse lakatsehang.
Ho koala
Likarabelo tsa lik'hemik'hale ka seleng ea electrolytic ke mohlala o tiileng oa kamoo motlakase o ka laolang phetoho ea lintho ka mekhoa ea redox. Ho cathode, hoa fokotseha, e leng se ka hlahisang tšepe e potlakileng kapa khase ea haedrojene, ha ho anode, ho etsahala oxidation, e ka hlahisang chlorine kapa khase ea oksijene. Litšebeliso tse ngata tsa indasteri tsa electrolysis li bontša hore ts'ebetso ena ha se mohopolo oa laboratori feela, empa ke motheo oa tlhahiso e ngata ea lik'hemik'hale ea sejoale-joale. Ka ho utloisisa liketso ho electrode ka 'ngoe le lintlha tse li susumetsang, re ka rala lits'ebetso tsa electrolysis tse sebetsang hantle, tse bolokehileng le tse theko e tlaase.
