concentrations NaF and KCl each 0.10 M in the cell

Suppose that the concentrations of NaF and KCl

were each 0.10 M in the cell

Pb(s) | PbF2(s) | F^-(aq) || Cl^-(aq) | AgCl(s) | Ag(s)

Using the half-reactions

2AgCl(s) + 2e^- ⇌ 2Ag(s) + 2Cl^- and

PbF2(s) + 2e^- ⇌ Pb(s) + 2F^-,

calculate the cell voltage.

[참고] 표준 환원 전위

> AgCl + e^- → Ag + Cl^- ... E° = +0.222 V

> PbF2(s) + 2e^- ⇌ Pb(s) + 2F^- ... E° = –0.350 V

2AgCl(s) + 2e^- ⇌ 2Ag(s) + 2Cl^-

Nernst 식

E = E° – (0.0592 V / n) × logQ

= E° – (0.0592 V / n) × log([생성물]/[반응물])

( 참고 https://ywpop.tistory.com/2900 )

= (+0.222) – (0.0592 / 2) × log((0.10)^2)

= +0.281 V

= E_red (환원전극)

PbF2(s) + 2e^- ⇌ Pb(s) + 2F^-

E = E° – (0.0592 V / n) × log([생성물]/[반응물])

= (–0.350) – (0.0592 / 2) × log((0.10)^2)

= –0.291 V

= E_ox (산화전극)

E_cell = E_red(환원전극) – E_red(산화전극)

= (환원된 물질의 환원전위) – (산화된 물질의 환원전위)

( 참고 https://ywpop.tistory.com/4558 )

= E_red – E_ox

= (+0.281) – (–0.291)

= +0.572 V

답: 0.572 V

[ 같은 글 https://ywpop.tistory.com/470631 ]

[키워드] 네른스트 기준