Exciting Calculation of Standard Emf in a Galvanic Cell!
How to calculate the standard emf of a galvanic cell?
Given the standard reduction potentials for Sn and Cu, how can we determine the standard emf of the galvanic cell?
Answer:
The standard emf (electromotive force) of the galvanic cell consisting of a Sn electrode and a Cu electrode at 25°C is 0.29 V.
To calculate the standard emf of the galvanic cell, we can use the Nernst equation, which relates the standard emf (E°cell) to the standard reduction potentials (E°) of the half-reactions involved:
E°cell = E°(cathode) - E°(anode)
In this case, Sn is undergoing reduction (acts as the cathode), and Cu is undergoing oxidation (acts as the anode). The standard reduction potentials are:
- E°(Sn²⁺/Sn) = -0.14 V
- E°(Cu²⁺/Cu) = 0.15 V
Now, we can calculate the standard emf of the cell:
E°cell = E°(cathode) - E°(anode)
E°cell = (0.15 V) - (-0.14 V)
E°cell = 0.15 V + 0.14 V
E°cell = 0.29 V
Therefore, the standard emf of the galvanic cell at 25°C is 0.29 V. This positive value indicates that the cell is capable of producing electrical energy as spontaneous redox reactions occur.