If ΔG° is negative and K > 1, which statement best describes the reaction?

If ΔG° is negative and K > 1, which statement best describes the reaction?

• A. the rxn is nonspontaneous (reactants are favored)
• B. the reaction is endothermic
• C. the rxn is spontaneous (products are favored)
• D. the rxn is at equilibrium with equal amounts

Answer: (C)

Negative ΔG° means the reaction can proceed on its own under standard conditions. The relation ΔG° = -RT ln K links this to the equilibrium constant: a negative ΔG° makes ln K positive, so K is greater than 1. That means at equilibrium there are more products than reactants, so the reaction moves forward and is product-favored. The other details aren’t determined by ΔG° alone—endothermic versus exothermic depends on enthalpy and entropy, and equal amounts would correspond to K = 1, which isn’t the case here since K > 1.

Negative ΔG° means the reaction can proceed on its own under standard conditions. The relation ΔG° = -RT ln K links this to the equilibrium constant: a negative ΔG° makes ln K positive, so K is greater than 1. That means at equilibrium there are more products than reactants, so the reaction moves forward and is product-favored. The other details aren’t determined by ΔG° alone—endothermic versus exothermic depends on enthalpy and entropy, and equal amounts would correspond to K = 1, which isn’t the case here since K > 1.