Question

Using standard potential, calculate the standard cell potential and the equilibrium constants for the following reactions:
Cu(s) + 2Ag+(aq) -> Cu2+(aq) + 2Ag(s)
Zn(s) + Fe2+(aq) -> Zn2+(aq) + Fe(s)

Answer 1

i think that's how u do for A
a.
Cu²⁺(aq) + 2e⁻ ⇌ Cu(s) ; E° = 0.340V
Ag⁺(aq) + e⁻ ⇌ Ag(s) ; E° = 0.7996V
=>
Cu(s) ⇌ Cu²⁺(aq) + 2 e⁻ ; E° = -0.34V
2Ag⁺(aq) + 2e⁻ ⇌ Ag(s) ; E° = 2∙7996V = 1.5992V
=>
Cu(s) + 2 Ag⁺(aq) ⇌ Cu²⁺(aq) + 2 Ag(s) ;
E° = -0.340V - 1.5992.4V = 1.2592V
=>
K = e^(38.941V⁻¹ ∙ 2 ∙ 1.2592V )
= e^( 98.069)
= 3.90×10⁴²