Imibuzo Eyisibonelo Ekhuluma Ngamaseli E-Voltaic
I-Pendahuluan
Iseli le-voltaic, elaziwa nangokuthi iseli le-galvanic, liyithuluzi eliguqula amandla amakhemikhali abe amandla kagesi ngokusebenzisa ukusabela kwe-redox (ukunciphisa i-oxidation). Iseli le-voltaic liqukethe ama-electrode amabili, ngokuvamile enziwe ngezinsimbi ezingafani, acwiliswe ku-electrolyte futhi axhunywe yibhuloho likasawoti. Kulesi sihloko, sizoxoxa ngezibonelo eziningana ezihlobene namaseli e-voltaic ukuze sijulise ukuqonda kwethu izimiso zawo zokusebenza kanye nendlela yokubala amandla eseli.
Umbono Oyisisekelo Wamaseli E-Voltaic
Ngaphambi kokuqhubekela ezinkingeni zesibonelo, kubalulekile ukuqonda imiqondo eyisisekelo kanye nezingxenye ezakha iseli le-Voltaic:
1. I-Anode kanye ne-Cathode: Kuseli le-Voltaic, i-anode iyi-electrode lapho kwenzeka khona i-oxidation, kanti i-cathode iyi-electrode lapho kwenzeka khona ukuncipha. I-anode ine-negative charge, kanti i-cathode ine-positive charge.
2. Indlela Yama-Electron: Ama-electron ageleza esuka ku-anode aye ku-cathode ngesekethe yangaphandle, akhiqize ugesi.
3. Amandla Eseli (i-E°cell): Amandla eseli umehluko ongaba khona phakathi kwama-electrode amabili. Amandla eseli ajwayelekile (i-E°cell) angabalwa kusetshenziswa ifomula:
\[
E°cell = E°cathode – E°anode
\]
lapho i-\(E°cathode\) kanye ne-\(E°anode\) kuyizindlela zokunciphisa ezijwayelekile ze-cathode kanye ne-anode.
4. Ibhuloho Likasawoti: Leli bhuloho lilinganisa izindleko ze-ion kuzo zombili izixazululo ze-electrolyte ngokuvumela ukunyakaza kwama-ion.
Imibuzo Eyisibonelo Nengxoxo
Ukuze sicacise le mibono, ake sixoxe ngezinkinga ezithile eziyisibonelo.
Isibonelo Umbuzo 1
Umbuzo:
Bala amandla eseli ajwayelekile eseli le-Volta aqukethe ama-electrode e-Zn | Zn²⁺ (aq) kanye nama-electrode e-Cu | Cu²⁺ (aq). Kuyaziwa ukuthi amandla okunciphisa ajwayelekile \(E°\) e-Zn²⁺ | Zn ngu--0.76 V kanye \(E°\) e-Cu²⁺ | Cu ngu-+0.34 V.
Ingxoxo:
Isinyathelo sokuqala ukuthola ukuthi iyiphi i-anode kanye ne-cathode.
I-Zn inamandla okunciphisa amabi kakhulu (-0.76 V) kune-Cu (+0.34 V), ngakho-ke i-Zn izosebenza njenge-anode (indawo yokuxilisa) kanye ne-Cu njenge-cathode (indawo yokunciphisa).
Okulandelayo, sisebenzisa ifomula:
\[
E°cell = E°cathode – E°anode
\]
Faka amanani aziwayo esikhundleni sawo:
\[
Iseli le-E = 0.34 V – (-0.76 V)
\]
\[
Iseli le-E = 0.34 V + 0.76 V
\]
\[
Iseli le-E° = 1.10 V
\]
Ngakho-ke, amandla ajwayelekile weseli yi-1.10 V.
Isibonelo Umbuzo 2
Umbuzo:
Iseli le-Voltaic lenziwe ngama-electrode e-Fe | Fe²⁺ kanye nama-electrode e-Ag | Ag⁺. Amandla okunciphisa ajwayelekile e-Fe²⁺ | Fe angu--0.44 V kanye ne-Ag⁺ | Ag angu-+0.80 V. Bala amandla eseli ajwayelekile bese ubhala ukusabela kweseli.
Ingxoxo:
Njengangaphambili, sidinga ukunquma i-anode kanye ne-cathode. Njengoba amandla okunciphisa i-Fe²⁺/Fe engemihle kakhulu kune-Ag⁺/Ag, i-Fe izosebenza njenge-anode kanye ne-Ag njenge-cathode.
Sebenzisa ifomula:
\[
E°cell = E°cathode – E°anode
\]
\[
Iseli le-E = 0.80 V – (-0.44 V)
\]
\[
Iseli le-E = 0.80 V + 0.44 V
\]
\[
Iseli le-E° = 1.24 V
\]
Amandla eseli ajwayelekile angu-1.24 V.
Ukuze sithole impendulo yeseli iyonke, sihlanganisa ukusabela kwe-oxidation kanye nokunciphisa:
– Ukusabela ku-anode: \( \text{Fe} \rightarrow \text{Fe}^{2+} + 2\text{e}^- \)
– Ukusabela ku-cathode: \( \text{Ag}^+ + \text{e}^- \rightarrow \text{Ag} \)
Ukulinganisela inani lama-electron kuzo zombili izindlela zokusabela:
\[
\text{Fe} \rightarrow \text{Fe}^{2+} + 2\text{e}^-
\]
\[
2\umbhalo{Ag}^+ + 2\umbhalo{e}^- \umcibisholo ongakwesokudla 2\umbhalo{Ag}
\]
Ukusabela kweseli sekukonke:
\[
\text{Fe} + 2\text{Ag}^+ \rightarrow \text{Fe}^{2+} + 2\text{Ag}
\]
Isibonelo Umbuzo 3
Umbuzo:
Bala amandla eseli ku-25°C ngeseli le-Voltaic eliqukethe ama-electrode e-Al | Al³⁺ kanye nama-electrode e-Ni | Ni²⁺, uma ukuhlushwa kwe-Al³⁺ kungu-0.001 M kanti ukuhlushwa kwe-Ni²⁺ kungu-1 M. Kuyaziwa ukuthi \(E°\) ye-Al³⁺ | Al ingu--1.66 V kanye \(E°\) ye-Ni²⁺ | Ni ingu--0.23 V.
Ingxoxo:
Okokuqala, thola i-anode kanye ne-cathode:
– Amandla okunciphisa i-Al³⁺/Al aphansi kakhulu (-1.66 V) kune-Ni²⁺/Ni (-0.23 V), ngakho-ke i-Al iyi-anode kanti i-Ni iyi-cathode.
Amandla eseli ajwayelekile abalwa kanje:
\[
E°cell = E°cathode – E°anode
\]
\[
Iseli le-E = -0.23 V – (-1.66 V)
\]
\[
Iseli le-E = -0.23 V + 1.66 V
\]
\[
Iseli le-E° = 1.43 V
\]
Okulandelayo, sisebenzisa i-Nernst Equation ukubala amandla eseli ngaphansi kwezimo ezingezona ezejwayelekile:
\[
I-E_{cell} = I-E°cell – \kwesobunxele( \frac{RT}{nF} \kwesokudla) \ln Q
\]
Lapho \( Q = \frac{[\text{Al}³⁺]}{[\text{Ni}²⁺]} \), u-R uyi-gas constant (8.314 J/mol·K), u-T uyi-temperature ku-Kelvin (298 K ku-25°C), u-F uyi-Faraday constant (96485 C/mol), kanti u-n yinombolo yama-electron (6 yokusabela okubandakanya i-Al³⁺ ne-Ni²⁺).
Faka amanani aziwayo ku-equation:
\[
Q = \frac{0.001}{1} = 0.001
\]
\[
I-E_{cell} = 1.43 V – \kwesobunxele( \frac{8.314 \izikhathi ezingu-298}{6 \izikhathi ezingu-96485} \kwesokudla) \ln 0.001
\]
\[
I-E_{cell} = 1.43 V – \left( \frac{2477.172}{578910} \right) \ln 0.001
\]
\[
Iseli_le-E_{iseli} = 1.43 V – (0.00428) \ln 0.001
\]
\[
\ln 0.001 = -6.907
\]
\[
I-E_{cell} = 1.43 V – (0.00428 \izikhathi -6.907)
\]
\[
Iseli_le-E_{iseli} = 1.43 V + 0.0295
\]
\[
I-E_{cell} = 1.4595 V
\]
Ngakho-ke, amandla eseli kulesi simo angaba ngu-1.46 V.
Isiphetho
Iseli le-voltaic liwumqondo oyisisekelo ku-electrochemistry oguqula amandla amakhemikhali abe amandla kagesi. Lesi sihloko sethule izisekelo zethiyori yamaseli e-voltaic futhi sanikeza izibonelo zokusiza ukucacisa inqubo yokubala amandla amaseli. Ngalokhu kuqonda, abafundi banethemba lokuthi bazoba nokuqonda okungcono ngamaseli e-voltaic kanye nokusetshenziswa kwawo ezimweni ezahlukene.
