**Calculating Delta G for an Al-Air Battery**

To calculate the delta G (change in Gibbs free energy) for an Al-air battery, we need to use the Nernst equation, which relates the electromotive force (Ecell) of a cell to the standard cell potential (E°cell) and the reaction quotient (Q):

Ecell = E°cell - (RT/nF) * ln(Q)

Where:
- Ecell is the measured cell potential
- E°cell is the standard cell potential
- R is the gas constant (8.314 J/(mol*K))
- T is the temperature in Kelvin
- n is the number of electrons involved in the cell reaction
- F is Faraday's constant (96,485 C/mol)
- ln is the natural logarithm
- Q is the reaction quotient

Given:
- Ecell = 2.73 V
- n = 12 (12 electrons process)

**Calculating Delta G**

Since we're given the Ecell and n, we can rearrange the Nernst equation to solve for the delta G:

Delta G = -nF * Ecell

Plugging in the given values:

Delta G = -12 * 96,485 C/mol * 2.73 V

We need to convert volts (V) to joules (J) because the unit for Faraday's constant is coulombs (C):

1 V = 1 J/C

Therefore:

Delta G = -12 * 96,485 C/mol * 2.73 J/C = -3,141,297 J/mol

Converting from joules to kilojoules:

1 kJ = 1000 J

Delta G = -3,141,297 J/mol / 1000 = -3141.297 kJ/mol

Thus, the delta G for the Al-air battery process is -3141.297 kJ/mol.

**Explanation:**

The delta G represents the change in Gibbs free energy, which tells us whether a reaction is energetically favorable or unfavorable. In this case, the negative value of delta G (-3141.297 kJ/mol) indicates that the reaction is spontaneous and releases energy. The larger the magnitude of the negative delta G, the more energetically favorable the reaction.