Final answer:
To find the standard cell potential (E°) for a galvanic cell, use the formula ΔG° = -nFE°. Substituting ΔG° = -7.9 kJ/mol, n = 3, and F = 96,500 J/(V·mol), E° is calculated to be 0.027 V.
Step-by-step explanation:
To determine the standard cell potential (E°) for a galvanic cell when the standard free energy change (ΔG°) is given, we can use the relationship ΔG° = -nFE°, where n represents the number of moles of electrons transferred and F is the Faraday's constant. Given that ΔG° = -7.9 kJ/mol for the reaction and n = 3, along with the value of F = 96,500 J/(V·mol), we can solve for E°.
To convert units from kJ to J, we multiply by 1,000, getting ΔG° = -7,900 J/mol. Rearranging the equation to solve for E° gives us E° = -ΔG°/(nF). Substituting the known values results in E° = -(-7,900 J/mol) / (3 · 96,500 J/(V·mol)), which simplifies to E° = 0.027 V. Therefore, the standard cell potential for this galvanic cell is 0.027 V.