Su'aalo Tusaale ah oo Ka Hadlaya Isticmaalka Xogta Suurtagalka ah ee Elektrode-ka Caadiga ah
Awoodda elektroodka caadiga ah (E°) waxay door muhiim ah ka ciyaartaa kiimikada, gaar ahaan fahamka falcelinta redox iyo elektrookiimika. Waxay bixisaa hab lagu saadaaliyo jihada falcelinta redox iyo isbarbardhigga awoodaha wakiilada oksaydhka iyo yaraynta. Maqaalkani wuxuu soo bandhigi doonaa dhowr tusaale oo ku saabsan isticmaalka xogta suurtagalka elektroodka caadiga ah si loo muujiyo codsigeeda xaaladaha dhabta ah.
Hordhac ku saabsan Awoodaha Elektrode-ka Caadiga ah
Awoodda elektroodka caadiga ah waxay cabbirtaa u janjeersiga curiye ama isku-dhis si uu u helo ama u lumiyo elektroonada xaaladaha caadiga ah (1 M, 1 atm, iyo 25°C). Awoodda elektroodka caadiga ah waxaa lagu muujiyaa volts (V) waxaana badanaa la barbar dhigaa awoodda elektroodka haydarojiin ee caadiga ah (SHE), taas oo loo qaato 0 V.
Su'aal Tusaale ah 1: Go'aaminta Falcelinta Iskeed ah
Su'aal:
Xisaabi in falcelinta soo socota ay si kedis ah u dhici doonto:
\[ \qoraalka{Zn}^{2+} + \qoraalka{Cu} \rightarrow \qoraalka{Zn} + \qoraalka{Cu}^{2+} \]
Awoodda elektroodka caadiga ah ee loo baahan yahay waa:
– \(\text{Zn}^{2+} + 2e^{-} \rightarrow \text{Zn} \) \( E° = -0.76 \, \text{V} \)
– \(\text
Dood:
1. Qeex falcelinta Nuska Unugyada:
Hoos u dhigista falgalka nus-unug:
– Falcelinta kala-badh ee oksaydhaynta: \[\text{Zn}^{2+} + 2e^{-} \rightarrow \text{Zn} \, \text{(Yaraynta, E° = -0.76 V)} \]
– Hoos u dhigista falcelinta nus-falcelinta: \[\text{Cu}^{2+} + 2e^{-} \rightarrow \text{Cu} \, \text{(Yaraynta, E° = +0.34 V)} \]
2. Aqoonsiga Falcelinta:
Dib u celi falgalka leh awood hoose si uu u noqdo oksaydh:
– \[\text{Zn} \rightarrow \text{Zn}^{2+} + 2e^{-} \, \text{(Oxidation, E° = +0.76 V)} \]
Falcelinta hartay:
– \[\text{Cu}^{2+} + 2e^{-} \qoraalka saxda ah \text{Cu} \, \text{( dhimis, E° = +0.34 V)} \]
3. Xisaabi wadarta guud ee E° (kartida unugyada):
– \[ E°_{\text{cell}} = E°_{\text{reduction}} + E°_{\text{oxidation}} = +0.34 \, \text{V} + (+0.76 \, \text{V}) = +1.10 \, \text{V} \]
Maadaama awoodda unugga (E°_{\text{cell}}) ay tahay mid togan, falcelintani waa mid iskeed ah.
Su'aal Tusaale 2: Go'aaminta Suurtagalnimada Sinnaanta
Su'aal:
Xisaabi awoodda unugga ee falgalka soo socda heerkulka caadiga ah:
\[ \text{Fe}^{2+} + \text{Ag} \rightarrow \text{Fe} + \text{Ag}^{+} \]
Awoodda elektroodka caadiga ah:
– \(\text{Fe}^{2+} + 2e^{-} \rightarrow \text{Fe} \) \( E° = -0.44 \, \text{V} \)
– \(\text{Ag}^{+} + e^{-} \rightarrow \text{Ag} \) \( E° = +0.80 \, \text{V} \)
Dood:
1. Qeex falcelinta Nuska Unugyada:
Hoos u dhigista falgalka nus-unug:
– \[\text{Fe}^{2+} + 2e^{-} \rightarrow \text{Fe} \, \text{(Yaraynta, E° = -0.44 V)} \]
– \[\text{Ag}^{+} + e^{-} \rightarrow \text{Ag} \, \text{(Yaraynta, E° = +0.80 V)} \]
2. Aqoonso Kala-Falcelin Badh ah:
Dib u celi falcelinta leh qiime taban oo yar (oo ka wanaagsan):
– \[\text{Fe} \rightarrow \text{Fe}^{2+} + 2e^{-} \, \text{(Oxidation, E° = +0.44 V)} \]
Falcelinta hartay:
– \[\text{Ag}^{+} + e^{-} \rightarrow \text{Ag} \, \text{(Yaraynta, E° = +0.80 V)} \]
3. Xisaabi wadarta guud ee E° (kartida unugyada):
– \[ E°_{\text{cell}} = E°_{\text{reduction}} + E°_{\text{oxidation}} = +0.80 \, \text{V} + (+0.44 \, \text{V}) = +1.24 \, \text{V} \]
Awoodda unugyada togan waxay muujinaysaa in falgalkani uu si iskiis ah u socdo xaaladaha caadiga ah.
Tusaale 3: Xisaabinta Tamarta Bilaashka ah ee Gibbs
Su'aal:
Go'aami isbeddelka tamarta xorta ah ee Gibbs (ΔG) ee falcelinta soo socota:
\[ \text{Al} + \text{Cu}^{2+} \rightarrow \text{Al}^{3+} + \text{Cu} \]
Marka la eego awoodda elektroodka caadiga ah:
– \(\text{Al}^{3+} + 3e^{-} \rightarrow \text{Al} \) \( E° = -1.66 \, \text{V} \)
– \(\text
Dood:
1. Qeex falcelinta Nuska Unugyada:
Hoos u dhigista falgalka nus-unug:
– \[\text{Al}^{3+} + 3e^{-} \rightarrow \text{Al} \, \text{(Yaraynta, E° = -1.66 V)} \]
– \[\text{Cu}^{2+} + 2e^{-} \qoraalka saxda ah \text{Cu} \, \text{( dhimis, E° = +0.34 V)} \]
2. Aqoonsiga Falcelinta:
Dib u celi falgalka leh awood hoose si uu u noqdo oksaydh:
– \[\text{Al} \rightarrow \text{Al}^{3+} + 3e^{-} \, \text{(Oxidation, E° = +1.66 V)} \]
Falcelinta hartay:
– \[\text{Cu}^{2+} + 2e^{-} \qoraalka saxda ah \text{Cu} \, \text{( dhimis, E° = +0.34 V)} \]
3. Dheelitirka Elektarooniga:
Isle'eg tirada elektaroonada falgalka:
– 2 \(\text{Al} \rightarrow 2\text{Al}^{3+} + 6e^{-} \) \[\text{(Oxidation, E° = +1.66 V)} \]
– 3 \(\text{Cu}^{2+} + 6e^{-} \rightarrow 3\text{Cu} \) \[\text{(Reduction, E° = +0.34 V)} \]
4. Xisaabi wadarta guud ee E° (kartida unugyada):
– \[ E°_{\text{cell}} = (+0.34 \, \text{V} \times 3) + (+1.66 \, \text{V} \times 2) \]
Khalad halkan: Celcelis:
– \[ E°_{\text{cell}} = +0.34 \, \text{V} + +1.66 \, \text{V} = +2.00 \, \text{V}\]
5. Xisaabi ΔG:
Qaacidda: \(\Delta G = -nFE_{\text{cell}}\)
– \[n = 6 \, \qoraalka{elektroonada} \]
– \[F = 96485 \, \qoraalka{C/mol} \]
– \[ \Delta G = -6 \times 96485 \, \text{C/mol} \times +2.00 \, \text{V}\]
- \[ = -1157820 \, \ qoraal {J/mol} \]
- \[ = -1157.82 \, \ qoraal {kJ/mol} \]
Sidaa darteed, ΔG taban waxay muujinaysaa in falcelintani ay tahay mid aan iskeed u dhicin.
Gabagabo
Xogta suurtagalka ah ee elektroodka caadiga ah waxay bixisaa hab wax ku ool ah oo lagu saadaaliyo jihada falcelinta redox ay u socon doonto, sida ay u badan tahay inay u socoto, iyo xiriirka ay la leedahay isbeddelka tamarta xorta ah ee Gibbs. Dhibaatada tusaalaha ah ee kor ku xusan waxay muujinaysaa sida xogtan loogu isticmaali karo in lagu go'aamiyo iskeed u kacda falcelinta redox iyo xisaabinta tamarta ee la xiriirta. Ardayda ama qof kasta oo baranaya kiimikada, fahamka xogta suurtagalka elektroodka caadiga ah iyo codsiyadeeda waa aasaas muhiim u ah fahamka falcelinta elektroodka ee adag.
