The nickel-cadmium battery cell has a standard potential of +1.20 V.The cell reaction is 2 NiO(OH) (s) + Cd(s) + 2 H₂O(l) → 2 Ni(OH) ₂(s) + Cd(OH) ₂(s) .
What is the standard free energy change for this reaction?

Question

Quizplus · Accepted Answer

The formula for calculating standard free energy change (∆G°) is:
∆G° = -nFE°
where n is the number of moles of electrons transferred in the reaction, F is Faraday's constant (96,485 C/mol), and E° is the standard cell potential.
In this case, n = 2 (since two electrons are transferred in the reaction), F = 96,485 C/mol, and E° = +1.20 V.
Plugging in the values:
∆G° = -2 × 96,485 C/mol × (+1.20 V) = -232,164 J/mol = -232 kJ/mol (since ∆G° is usually expressed in kJ/mol).
Therefore, the correct answer is C.

The Nickel-Cadmium Battery Cell Has a Standard Potential of +1