Question

A galvanic (voltaic) cell consists of an electrode composed of aluminum in a 1.0 M aluminum ion solution and another electrode composed of silver in a 1.0 M silver ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C_______________.. Refer to the list of standard reduction potentials.

Answer 1

Answer:

E° = 2.46 V

Explanation:

We have a voltaic cell of aluminum and silver in their respective solutions. To know where will take place the reduction (cathode) and where will take place the oxidation (anode), we need to compare the standard reduction potentials.

E°(Al³⁺/Al) = -1.66 V

E°(Ag⁺/Ag) = +0.80 V

Since Ag⁺/Ag has the highest reduction potential that is where reduction will take place while oxidation will take place in the Al electrode.

Reduction (cathode): Ag⁺(aq) + 1 e⁻ ⇒ Ag(s)

Oxidation (anode): Al(s) ⇒ Al³⁺(aq) + 3 e⁻

The standard potential of the cell (E°) is the difference between the reduction potential of the cathode and the reduction potential of the anode.

E° = E°red,cathode - E°red,anode = 0.80 V - (-1.66V) = 2.46 V