Question

Consider a galvanic cell built on the following half-reactions with their standard reduction potentials shown. What is ∆G° at 25 °C for the reaction involved?

1F = 96,485 J/mol e-

Cr2O72- + 14H+ + 6e- <=> 2Cr3+ + 7H2O E° = 1.20 V

H2O2 + 2H+ + 2e- <=> 2 H2O E ° = 1.75 V

Answer 1

Step-by-step explanation:

Cr272- + 14H+ + 6e- <=> 2Cr3+ + 7H2O E° = 1.20 V

(H2O2 + 2H+ + 2e- <=> 2H2O E ° = 1.75)x3

EMF of the cell = 1.75 x 3 - 1.20

E = 4.05 V

∆G° = - n E F

n = 6

E = 4.05

F = 96485

∆G° = - 6 x 4.05 x 96485

= - 2344585.5 J