Cov Lus Nug Piv Txwv Sib Tham Txog Kev Sib Piv ntawm Voltaic Cells thiab Electrolytic Cells
Kev sib piv ntawm cov hlwb voltaic thiab cov hlwb electrolytic yog ib qho tseem ceeb hauv chemistry, tshwj xeeb tshaj yog hauv kev kawm txog electrochemistry. Ob qho tib si yog cov khoom siv siv los tsim hluav taws xob los ntawm cov tshuaj lom neeg lossis los coj cov tshuaj lom neeg los ntawm kev siv lub zog hluav taws xob. Tsab xov xwm no yuav qhia txog qhov sib txawv tseem ceeb ntawm cov hlwb voltaic thiab cov hlwb electrolytic los ntawm cov teeb meem piv txwv thiab kev sib tham. Lub hom phiaj yog los muab kev nkag siab tob thiab tob txog ob hom hlwb.
Lub Cell Voltaic
Lub cell voltaic, tseem hu ua galvanic cell, yog ib hom cell electrochemical uas tsim cov hluav taws xob los ntawm kev tshuaj lom neeg tsis tau npaj tseg. Hauv lub cell voltaic, qhov kev tshuaj ntsuam redox tshwm sim, qhov twg kev txo qis thiab oxidation tshwm sim ntawm cov electrodes sib txawv. Txhawm rau kom nkag siab qhov no zoo dua, cia peb saib ib qho piv txwv ntawm lub cell voltaic.
Piv txwv lus nug 1:
Lub anode ntawm lub cell voltaic yog ua los ntawm zinc (Zn) thiab cathode ntawm tooj liab (Cu). Xav tias kev sab laj nrog lub rooj ntawm cov peev xwm txo qis tus qauv qhia tau tias lub peev xwm txo qis tus qauv (E°) ntawm Cu²⁺/Cu yog +0,34 V thiab ntawm Zn²⁺/Zn yog -0,76 V. Xam lub peev xwm ntawm lub cell tus qauv (E° cell) ntawm lub cell voltaic no.
Kev Sib Tham:
Ua ntej, sau cov tshuaj tiv thaiv ib nrab ntawm lub hlwb rau kev oxidation thiab kev txo qis.
– Anode (Oxidation): Zn(s) → Zn²⁺(aq) + 2e⁻
- Cathode (Reduction): Cu²⁺(aq) + 2e⁻ → Cu(s)
Lub peev xwm ntawm lub cell txheem (E° cell) yog xam los ntawm qhov sib txawv ntawm lub peev xwm txo qis ntawm cathode thiab anode.
- E° cell = E° cathode – E° anode
– E° cathode = +0,34 V
– E° anode = -0,76 V
Yog li ntawd, tus qauv cell peev xwm yog:
\[ E°_{sel} = 0.34V – (-0.76V) \]
\[E°_{cell} = 0.34V + 0.76V \]
\[ E°_{sel} = 1.10V \]
Yog li, tus qauv cell muaj peev xwm rau lub cell voltaic no yog 1,10 V.
Lub Cell Hluav Taws Xob
Cov hlwb electrolytic, ntawm qhov tod tes, siv lub zog hluav taws xob los yuam kom cov tshuaj tsis tshwm sim. Hauv lub hlwb electrolytic, cov hluav taws xob los ntawm lwm qhov chaw raug siv los tsav cov tshuaj redox uas yuav tsis tshwm sim ntawm nws tus kheej. Cia peb saib ib qho piv txwv ntawm lub hlwb electrolytic kom nkag siab txog nws cov khoom thiab cov hauv paus ntsiab lus ua haujlwm.
Piv txwv lus nug 2:
Hauv cov txheej txheem electrolysis, txhuas yog tsim los ntawm cov txhuas oxide uas yaj (Al₂O₃). Xam qhov hluav taws xob uas xav tau los tsim 1 mole ntawm txhuas (Al). Xav tias ib mole ntawm Al xav tau peb moles ntawm electrons.
Kev Sib Tham:
Raws li cov qauv electrochemical rau electrolysis:
\[ Al^{3+}(aq) + 3e⁻ → Al(s) \]
Nws paub tias rau txhua mole ntawm txhuas, 3 moles ntawm electrons yog qhov xav tau. Raws li Faraday txoj cai, qhov hluav taws xob (Q) xav tau tuaj yeem suav nrog siv cov mis:
\[ Q = n \cdot F \]
Qhov twg:
-n yog tus naj npawb ntawm moles ntawm electrons
- F yog Faraday tus nqi tas mus li (96500 C/mol electrons)
Yuav tsim tau 1 mole ntawm Al:
\[ n = 3 \text{ moles ntawm electrons} \]
Yog li, qhov hluav taws xob (Q):
\[ Q = 3 \cdot 96500 \]
\[ Q = 289500 \text{ C} \]
Yog li, txhawm rau tsim 1 mole ntawm txhuas, 289500 coulombs ntawm hluav taws xob yuav tsum tau ua.
Kev Sib Piv ntawm Voltaic Cells thiab Electrolytic Cells
Cov lus hauv qab no qhia txog qhov sib txawv tseem ceeb ntawm cov hlwb voltaic thiab cov hlwb electrolytic:
| Cov Yam Ntxwv | Lub Cell Voltaic | Lub Cell Electrolytic |
|—————————–|——————————————|————————————–|
| Cov Chaw Siv Hluav Taws Xob | Cov Tshuaj Tiv Thaiv | Lub Zog Hluav Taws Xob |
| Hom kev ua teb | Ua rau nws tus kheej | Tsis ua rau nws tus kheej |
| Anode (-)/Cathode (+) | Anode (-), Cathode (+) | Anode (+), Cathode (-) |
| Lub Hom Phiaj | Tsim hluav taws xob | Ua rau muaj kev cuam tshuam tshuaj lom neeg |
| Cov Ntawv Thov | Cov roj teeb, cov roj teeb roj | Plating, casting hlau, refining |
Cov Khoom Siv Hluav Taws Xob:
Cov hlwb Voltaic tsim lub zog hluav taws xob los ntawm cov tshuaj lom neeg tshwm sim, thaum cov hlwb electrolytic siv lub zog hluav taws xob los ntawm lwm qhov chaw los yuam kom cov tshuaj tsis tshwm sim.
Hom Tshuaj Tiv Thaiv:
Hauv lub cell voltaic, qhov kev tshwm sim tsis tau npaj tseg ua rau cov electrons ntws los ntawm anode mus rau cathode los ntawm lub voj voog sab nraud. Hauv lub cell electrolytic, ib qho hluav taws xob sab nraud siv los tsav ib qho kev tshwm sim uas yuav tsis tshwm sim ntawm nws tus kheej.
Anode thiab Cathode:
Hauv lub cell voltaic, lub anode yog lub electrode tsis zoo thiab lub cathode yog lub electrode zoo. Hauv lub cell electrolytic, lub anode yog lub electrode zoo thiab lub cathode yog lub electrode tsis zoo. Qhov no yog ib qho ntawm qhov sib txawv tseem ceeb uas feem ntau ua rau cov tub ntxhais kawm tsis meej pem.
Tujuan:
Lub hom phiaj tseem ceeb ntawm lub cell voltaic yog los tsim hluav taws xob, thaum lub cell electrolytic siv los ua kom muaj kev tshuaj lom neeg, xws li kev ua kom hlau zoo lossis dej electrolysis.
Cov ntawv thov:
Cov roj teeb Voltaic feem ntau siv rau hauv cov roj teeb thiab cov roj teeb roj, uas tsim hluav taws xob rau ntau yam kev siv. Cov roj teeb Electrolytic siv rau hauv cov txheej txheem kev lag luam xws li kev casting hlau, electroplating, thiab kev ua kom hlau zoo.
Xaus
Ob lub hlwb voltaic thiab electrolytic ua lub luag haujlwm tseem ceeb hauv kev siv tshuab niaj hnub no. Kev nkag siab txog txhua hom hlwb ua haujlwm li cas thiab yuav ua li cas xam cov kev ntsuas sib txawv los ntawm cov teeb meem piv txwv yog qhov tseem ceeb rau kev tswj hwm cov tswv yim electrochemistry. Hauv kev sib tham saum toj no, peb tau hais txog qhov sib txawv tseem ceeb ntawm cov hlwb voltaic thiab electrolytic, suav nrog lawv cov peev txheej zog, hom kev ua haujlwm, thiab piv txwv ntawm lawv cov ntawv thov hauv lub neej txhua hnub.
Nrog kev nkag siab zoo txog ob hom hlwb no, koj yuav npaj tau zoo dua los daws ntau yam teeb meem ntsig txog kev xeem chemistry thiab siv rau ntau yam cuab yeej thiab thev naus laus zis niaj hnub.
