Sketch the galvanic cell of reaction between Mg and Al and flow of electron, overall cell balance , half reaction and calculate the Ecell ?

1 answer

The reaction between Mg and Al can be represented as:

Mg (s) + 2Al3+ (aq) -> Mg2+ (aq) + 2Al (s)

The half reactions are:

Mg (s) -> Mg2+ (aq) + 2e- E° = -2.37 V
Al3+ (aq) + 3e- -> Al (s) E° = -1.66 V

The overall cell reaction is the sum of the half reactions:

Mg (s) + 2Al3+ (aq) -> Mg2+ (aq) + 2Al (s)

The overall cell balance is:

Anode: Mg (s) -> Mg2+ (aq) + 2e-
Cathode: Al3+ (aq) + 3e- -> Al (s)

The flow of electrons in the cell is from the anode to the cathode.

To calculate the Ecell, we use the formula:

Ecell = Ecathode - Eanode

Ecell = (-1.66 V) - (-2.37 V)
Ecell = 0.71 V

Therefore, the Ecell for the reaction between Mg and Al is 0.71 V.