Question

Calculate the equilibrium constant at 25 ∘C for the reaction Fe(s)+2Ag+(aq)→Fe2+(aq)+2Ag(s)

Answer 1

Answer:

1.7 × 10 ^42

Explanation:

Using Nernst equation

E°cell = RT/nF Inq

at equilibrium

Q=K

E°cell  = 0.0257 /n Ink= 0.0592/n log K

Fe2+(aq)+2e−→Fe(s)     E∘= −0.45 V

Ag+aq)+e−→Ag(s)         E∘= 0.80 V

Fe(s)+2Ag+(aq)→Fe2+(aq)+2Ag(s)

balance the reaction

Fe → Fe²⁺ + 2e⁻  reversing for oxidation E° = 0.45 v

2 Ag⁺ +2e⁻ → 2Ag

n = 2 moles  and K = equilibrium constant

E° cell = 0.80 + 0.45 = 1.25 V

E° cell = (0.0592 / n) log K  

substitute the value into the equations and solve for K

(1.25 × 2) / 0.0592  = log K

42.23 = log K

k = 10^ 42.23

K = 1.7 × 10 ^42