Calculate the cell potential for the galvanic cell in which the given reaction occurs at 25 °C.

Question

Calculate the cell potential for the galvanic cell in which the given reaction occurs at 25 °C, given that [Sn2+]=0.0576 M , [Co3+]=0.0322 M , [Sn4+]=0.00271 M , and [Co2+]=0.01024 M . Standard reduction potentials can be found in this table.

Sn2+(aq)+2Co3+(aq)↽−−⇀ Sn4+(aq)+2Co2+(aq)

Answer 1

From a table of standard reduction potentials:

Sn⁴⁺ + 2e- ===> Sn²⁺ Eº = + 0.15 V

Co³⁺ + e- ===> Co²⁺ Eº = +1.82 V

From a table of standard reduction potentials:

Sn4+ + 2e- ==> Sn2+ Eº = +0.15 V

Co3+ + e- ===> Co2+ Eº = +1.82 V

Sn²⁺ + 2Co³⁺ <===> Sn⁴⁺ + 2Co²⁺ with the transfer of 2 electrons.

Eº = 1.82 - 0.15 = 1.67

Q = [Sn⁴⁺][Co²⁺]²/[Sn²⁺][Co³⁺]² = (0.00271)(0.01024)² /(0.0576)(0.0322)² = 0.004758

E_cell = Eº -(0.0591/n) log Q = 1.67 - (0.02955) log 0.004758

E_cell = 1.67 - (-0.0686)

E_cell = 1.74 V

CAUTION: Do check my math !!