Final answer:
To ensure a spontaneous reaction, the Gibbs free energy change (ΔG) must be negative, which often corresponds to a large reaction quotient (K).
Step-by-step explanation:
To ensure a spontaneous reaction, the value of the Gibbs free energy change (ΔG) must be negative. This indicates that the reaction can occur without an input of energy from the surroundings. In terms of the reaction quotient (K), if ΔG is negative, this typically corresponds to a large K value, suggesting the reaction favors the formation of products and can proceed to near completion. Conversely, a positive ΔG indicates a non-spontaneous reaction that requires input of energy to proceed and correlates with a small K value.
It's important to remember that temperature in the Gibbs free energy equation is in Kelvin and can only have a positive value. When the enthalpy change (ΔH) is negative and the entropy change (ΔS) is positive, the reaction will be spontaneous at all temperatures, corresponding to conditions favoring product formation.