<u>Answer:</u>
<u>For a:</u> The standard Gibbs free energy of the reaction is -347.4 kJ
<u>For b:</u> The standard Gibbs free energy of the reaction is 746.91 kJ
<u>Explanation:</u>
Relationship between standard Gibbs free energy and standard electrode potential follows:
............(1)
The given chemical equation follows:

<u>Oxidation half reaction:</u>
( × 2)
<u>Reduction half reaction:</u> 
We are given:

Putting values in equation 1, we get:

Hence, the standard Gibbs free energy of the reaction is -347.4 kJ
The given chemical equation follows:

<u>Oxidation half reaction:</u>
( × 6)
<u>Reduction half reaction:</u> 
We are given:

Putting values in equation 1, we get:

Hence, the standard Gibbs free energy of the reaction is 746.91 kJ