Muenzaniso weMibvunzo yeKukurukurirana paStandard Reference Electrode Potential
Pendauluan
Electrochemistry ibazi rekemesitiri rinoongorora hukama huripo pakati pemakemikari nezviitiko zvemagetsi. Imwe yepfungwa huru mu electrochemistry i electrode potential. Electrode potential chiyero chemaitiro e electrode ekukwezva kana kuburitsa ma electron.
Mu electrochemistry, chiyero chinowanzoshandiswa i hydrogen electrode (SHE). Iyo SHE inotsanangurwa seine mukana we zero volts pakupisa kwese. Inoshanda sereferensi yepasi rose yekuyera nekuenzanisa potentials dzemamwe ma electrode. Chinyorwa chino chinangwa chekupa tsananguro yakadzama kuburikidza nemuenzaniso matambudziko ekukurukura kugona kwe standard reference electrode kukurudzira kunzwisisa kwakadzama.
Electrode Potential uye SHE
Iyo SHE inoshanda senzvimbo yekunongedzera ine electrode potential yakaiswa zvisina kurongeka pa 0 V. Equation ye hydrogen electrode reaction ndeiyi inotevera:
\[ 2H^+ (aq) + 2e^- \museve wekurudyi H_2 (g) \]
Mukuita, kutevedzera mamiriro ezvinhu eSHE kwakaoma kugadzira uye zvakajairika kushandisa mamwe ma electrode akajairika akadai seSaturated Calomel Electrode (SCE) kana Silver/Silver Chloride (Ag/AgCl).
Mibvunzo yemuenzaniso nehurukuro
Mubvunzo 1: Kuziva Kugona Kwemaerekitirodhi eSero reMaerekitirodhi
Mubvunzo:
Semuenzaniso, tinokumbirwa kuti tizive kuti masero anogona kuita sei pakati peZn(s) neCu^2+(aq). Zvinozivikanwa kuti electrode potential yakajairika yeZn^2+/Zn ndeye -0.76 V uye yeCu^2+/Cu ndeye +0.34 V. Ndeipi masero anogona kuita uchishandisa SHE sereferensi?
Jawaban:
Tinofanira kuverenga potential yemasero \( E_{cell} \) tichishandisa electrode potentials. Mhinduro yese iri mumasero ndeiyi:
\[ Zn(s) + Cu^{2+}(aq) \rightarrow Zn^{2+}(aq) + Cu(s) \]
Iyo electrode potential yakanyorwa seizvi:
\[ E_{sero} = E_{cathode} - E_{anode} \]
Apo cathode iri reduction reaction uye anode iri oxidation reaction. Zvichienderana ne standard potential:
- Cathode chiyero chinogona \( E^0_{cathode} \) (Cu^2+/Cu) = +0.34 V
– Simba re anode \( E^0_{anode} \) (Zn^2+/Zn) = -0.76 V
Kutsiva tsika:
\[ E_{sel} = 0.34 \, \text{V} – (-0.76 \, \text{V}) \]
\[ E_{sel} = 0.34 \, \text{V} + 0.76 \, \text{V} \]
\[ E_{cell} = 1.10 \, \text{V} \]
Saka, simba remasero i1.10 V.
Mubvunzo 2: Kushandisa Nernst Equation muNon-Standard Conditions
Mubvunzo:
Verengai mukana wemasero (E) pa298 K kuti muone mashandiro emagetsi pakati peZn(s) neCu^2+(aq) kana huwandu hweCu^2+ ions huri 0.01 M uye huwandu hweZn^2+ ions huri 1.00 M.
Jawaban:
Nernst equation inotipa nzira yekuverenga kugona kwesero kana mamiriro ezvinhu asiri e standard (asiri standard). Nernst equation ndeiyi:
\[ E = E^0 – \frac{RT}{nF} \ln Q \]
Di mana,
– \( E^0 \) ndiyo potential yakajairika yemasero
– \( R \) ndiyo gasi risingaperi (8.314 J/mol·K)
– \( T \) ndiyo tembiricha muKelvin (298 K)
– \( n \) inhamba yemamore emaerekitironi anotamiswa mukuita kwakaenzana (mamore maviri emaerekitironi eZn/Cu)
– \( F \) ndiyo nguva dzose yaFaraday (96485 C/mol)
– \( Q \) ndiyo mhinduro yemhinduro:
\[ Q = \frac{[zvigadzirwa]}{[reactants]} = \frac{[Zn^{2+}]}{[Cu^{2+}]} \]
Isa mavalues muNernst equation:
Potential yakajairika \( E^0 \) kubva padambudziko rapfuura i1.10 V.
\[ E = 1.10 \, \text{V} – \frac{8.314 \, \text{J/mol·K} \times 298 \, \text{K}}{2 \times 96485 \, \text{C/mol}} \ln \left(\frac{1.00}{0.01}\right) \]
Kutanga, verenga nguva yekupisa uye quotient ye reaction:
\[ \frac{8.314 \times 298}{2 \times 96485} = \frac{2476.652}{192970} \inenge 0.0128 \, \text{V} \]
Usakanganwa kuishandura kuti ienderane neJ kuenda kuVolts:
\[ \ln (100) = 4.605 \]
Saka:
\[ E = 1.10 \, \text{V} – 0.0128 \times 4.605 \]
\[ E = 1.10 \, \ zvinyorwa{V} – 0.0589584 \]
\[ E = 1.041 \, \chinyorwa{V} \]
Saka, kugona kwemasero pasi pemamiriro asina kujairika i1.041 V.
Mhedziso
Electrochemistry inzvimbo yakakosha ine mashandisirwo akawanda muindasitiri nesainzi. Kunzwisisa pfungwa huru dzakadai se electrode potential uye kushandiswa kweNernst equation kunotibvumira kuverenga masero ane simba pasi pemamiriro akasiyana-siyana. Mumuenzaniso uyu, taona maitiro ekuona masero ane simba tichishandisa standard reference electrode uye kuti zvinhu zvakaita se concentration zvinokanganisa sei masero ane simba.
Kukurukurirana uku kunoratidza kukosha kwekunzwisisa zvakadzama misimboti yemagetsi emagetsi kune akasiyana mashandisirwo, kubva kuma biosensors kusvika kumabhatiri. Izvi zvinopawo hwaro hwakasimba kune chero ani zvake anofarira kutsvagisa nekushandisa tekinoroji yemagetsi emagetsi.
