Which of the following statements most accurately describes the cell potential (E^o), change in Gibb’s free energy (ΔG^o), and equilibrium constant (K) for a non-spontaneous chemical reaction?

1. E^o < 0, ΔG^o > 0, K < 1
2. E^o < 0, ΔG^o < 0, K < 1
3. E^o > 0, ΔG^o < 0, K > 1
4. E^o > 0, ΔG^o > 0, K > 1

Explanation

This question is testing your understanding of the relationship between the change in standard free energy  (ΔG^o), electrochemical cell potential (E^o), and the equilibrium constant (K) for chemical reactions. To answer this question, you must apply the chemical principles relating to the equation, ΔG = -nFE_cell, and a derivative of the Nernst Equation, ΔG = ΔG^o + RTln(Q).

The question stem indicates that the chemical reaction is non-spontaneous, which corresponds to a positive change in standard free energy. According to the relationship between ΔG^o and E^o based on the equation ΔG^o = -nFE^o, a positive ΔG^o corresponds to a negative E^o. Thus, answer choices B and C can be eliminated. To determine the equilibrium constant, it is necessary to understand that the change in free energy of a chemical reaction (ΔG) is equal to zero and the reactant quotient (Q) is equal to the equilibrium constant (K). Thus, ΔG^o = -RTln(K). Since ΔG^o > 0, K < 1 making A the correct answer.

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