Mienzaniso yeMibvunzo Inokurukura Kushandiswa kweStandard Electrode Potential Data
Standard electrode potential (E°) inoita basa rakakosha mukemikari, kunyanya mukunzwisisa redox uye electrochemical reactions. Inopa nzira yekufanotaura mafambiro eredox reactions uye kuenzanisa simba re oxidizing uye reducing agents. Chinyorwa chino chichapa mienzaniso yakati wandei yekushandisa standard electrode potential data kuratidza mashandisirwo ayo mumamiriro ezvinhu chaiwo.
Nhanganyaya kuStandard Electrode Potentials
Iyo standard electrode potential inoyera maitiro echinhu kana compound ekuwana kana kurasikirwa nemaerekitironi pasi pemamiriro akajairwa (1 M, 1 atm, uye 25°C). Iyo standard electrode potential inoratidzwa mumavolts (V) uye inowanzo enzaniswa ne standard hydrogen electrode potential (SHE), iyo inotorwa se 0 V.
Muenzaniso Mubvunzo 1: Kuziva Maitiro Ekuzviitikira
Mubvunzo:
Verenga kana maitiro anotevera achizoitika ega:
\[ \text{Zn}^{2+} + \text{Cu} \rightarrow \text{Zn} + \text{Cu}^{2+} \]
Ma electrode potentials anodiwa ndeaya:
– \(\text{Zn}^{2+} + 2e^{-} \rightarrow \text{Zn} \) \( E° = -0.76 \, \text{V} \)
– \(\chinyorwa{Cu}^{2+} + 2e^{-} \museve wekurudyi \zvinyorwa{Cu} \) \( E° = +0.34 \, \chinyorwa{V} \)
Kukurukurirana:
1. Tsanangura Maitiro eHafu-Masero:
Kuderedza kuita kwehafu yemasero:
– Kubviswa kwe oxidation nehafu yemhinduro: \[\text{Zn}^{2+} + 2e^{-} \rightarrow \text{Zn} \, \text{(Reduction, E° = -0.76 V)} \]
– Kuderedza hafu yemhinduro: \[\text{Cu}^{2+} + 2e^{-} \rightarrow \text{Cu} \, \text{(Reduction, E° = +0.34 V)} \]
2. Kuziva Maitiro:
Dzorerai maitiro ane simba rakaderera kuitira kuti ave oxidation:
– \[\text{Zn} \rightarrow \text{Zn}^{2+} + 2e^{-} \, \text{(Oxidation, E° = +0.76 V)} \]
Maitiro asara:
– \[\ zvinyorwa{Cu}^{2+} + 2e^{-} \museve wekurudyi \zvinyorwa{Cu} \, \zvinyorwa{(Kuderedza, E° = +0.34 V)} \]
3. Verenga huwandu hwese hweE° (Sero rinogona kugoneka):
– \[ E°_{\text{cell}} = E°_{\text{reduction}} + E°_{\text{oxidation}} = +0.34 \, \text{V} + (+0.76 \, \text{V}) = +1.10 \, \text{V} \]
Sezvo potential yesero (E°_{\text{cell}}) iri yakanaka, maitiro aya anongoerekana aitika.
Muenzaniso Mubvunzo 2: Kuona Kuenzana Kwekuenzana
Mubvunzo:
Verenga kugona kwemasero kwekuita kunotevera patembiricha yakajairwa:
\[ \text{Fe}^{2+} + \text{Ag} \rightarrow \text{Fe} + \text{Ag}^{+} \]
Simba remagetsi rakajairika:
– \(\text{Fe}^{2+} + 2e^{-} \rightarrow \text{Fe} \) \( E° = -0.44 \, \text{V} \)
– \(\text{Ag}^{+} + e^{-} \rightarrow \text{Ag} \) \( E° = +0.80 \, \text{V} \)
Kukurukurirana:
1. Tsanangura Maitiro eHafu-Masero:
Kuderedza kuita kwehafu yemasero:
– \[\text{Fe}^{2+} + 2e^{-} \rightarrow \text{Fe} \, \text{(Reduction, E° = -0.44 V)} \]
– \[\text{Ag}^{+} + e^{-} \rightarrow \text{Ag} \, \text{(Reduction, E° = +0.80 V)} \]
2. Ziva Maitiro Ehafu:
Dzorera maitiro ane kukosha kudiki kwekusagadzikana (kwakanaka zvakanyanya):
– \[\text{Fe} \rightarrow \text{Fe}^{2+} + 2e^{-} \, \text{(Oxidation, E° = +0.44 V)} \]
Maitiro asara:
– \[\text{Ag}^{+} + e^{-} \rightarrow \text{Ag} \, \text{(Reduction, E° = +0.80 V)} \]
3. Verenga huwandu hwese hweE° (Sero rinogona kugoneka):
– \[ E°_{\text{cell}} = E°_{\text{reduction}} + E°_{\text{oxidation}} = +0.80 \, \text{V} + (+0.44 \, \text{V}) = +1.24 \, \text{V} \]
Kugona kwemasero kwakanaka kunoratidza kuti izvi zvinoitika zvoga mumamiriro ezvinhu akajairwa.
Muenzaniso 3: Kuverengwa kweGibbs Free Energy
Mubvunzo:
Sarudza shanduko muGibbs free energy (ΔG) yemhinduro inotevera:
\[ \text{Al} + \text{Cu}^{2+} \rightarrow \text{Al}^{3+} + \text{Cu} \]
Zvichienderana nehukuru hwe electrode:
– \(\text{Al}^{3+} + 3e^{-} \rightarrow \text{Al} \) \( E° = -1.66 \, \text{V} \)
– \(\chinyorwa{Cu}^{2+} + 2e^{-} \museve wekurudyi \zvinyorwa{Cu} \) \( E° = +0.34 \, \chinyorwa{V} \)
Kukurukurirana:
1. Tsanangura Maitiro eHafu-Masero:
Kuderedza kuita kwehafu yemasero:
– \[\text{Al}^{3+} + 3e^{-} \rightarrow \text{Al} \, \text{(Reduction, E° = -1.66 V)} \]
– \[\ zvinyorwa{Cu}^{2+} + 2e^{-} \museve wekurudyi \zvinyorwa{Cu} \, \zvinyorwa{(Kuderedza, E° = +0.34 V)} \]
2. Kuziva Maitiro:
Dzorerai maitiro ane simba rakaderera kuitira kuti ave oxidation:
– \[\text{Al} \rightarrow \text{Al}^{3+} + 3e^{-} \, \text{(Oxidation, E° = +1.66 V)} \]
Maitiro asara:
– \[\ zvinyorwa{Cu}^{2+} + 2e^{-} \museve wekurudyi \zvinyorwa{Cu} \, \zvinyorwa{(Kuderedza, E° = +0.34 V)} \]
3. Kuenzana kwemaerekitironi:
Enzanisa nhamba yema electron ekuita:
– 2 \(\text{Al} \rightarrow 2\text{Al}^{3+} + 6e^{-} \) \[\text{(Oxidation, E° = +1.66 V)} \]
– 3 \(\chinyorwa{Cu}^{2+} + 6e^{-} \museve wekurudyi 3\chinyorwa{Cu} \) \[\chinyorwa{(Kuderedza, E° = +0.34 V)} \]
4. Verenga huwandu hwese hweE° (Sero rinogona kugoneka):
– \[ E°_{\text{cell}} = (+0.34 \, \text{V} \times 3) + (+1.66 \, \text{V} \times 2) \]
Chikanganiso pano: Avhareji:
– \[ E°_{\text{cell}} = +0.34 \, \text{V} + +1.66 \, \text{V} = +2.00 \, \text{V}\]
5. Verenga ΔG:
Fomura: \(\Delta G = -nFE_{\text{cell}}\)
– \[n = 6 \, \mavara{maerekitironi} \]
– \[F = 96485 \, \text{C/mol} \]
– \[ \Delta G = -6 \nguva 96485 \, \chinyorwa{C/mol} \nguva +2.00 \, \chinyorwa{V}\]
- \[ = -1157820 \, \zvinyorwa{J/mol} \]
- \[ = -1157.82 \, \zvinyorwa{kJ/mol}\]
Saka, ΔG isina kunaka inoratidza kuti maitiro aya anongoerekana aitika.
Mhedziso
Data remagetsi emagetsi akajairika rinopa nzira inoshanda yekufanotaura kuti redox reaction ichaenderera mberi nekwairi, kuti ingangoenderera mberi sei, uye hukama hwayo nekuchinja kwesimba remagetsi reGibbs. Dambudziko remuenzaniso riri pamusoro rinoratidza kuti data iri rinogona kushandiswa sei kuona kuitika kweredox reaction uye kuverenga kwesimba kwakabatana. Kune vadzidzi kana chero ani zvake ari kudzidza chemistry, kunzwisisa data remagetsi emagetsi akajairika uye mashandisirwo aro ihwaro hwakakosha hwekunzwisisa maitiro akaomarara emagetsi.
