Explanation:

The Gibbs free energy change (ΔG) is a thermodynamic property that determines the spontaneity of a chemical reaction or physical process at constant temperature and pressure. It is related to the enthalpy change (ΔH) and entropy change (ΔS) through the equation:

ΔG = ΔH - TΔS

where T is the temperature in Kelvin.

The sign of ΔG determines whether a reaction or process is spontaneous or not. If ΔG is negative, the reaction or process is spontaneous, and if ΔG is positive, the reaction or process is non-spontaneous. When ΔG is zero, the reaction or process is at equilibrium.

Conditions for negative ΔG:

1. Negative enthalpy change (ΔH): If the enthalpy change (ΔH) is negative, it means that the reactants have a higher energy level than the products. In this case, the reaction will release energy, and ΔG will be negative. This condition is applicable when the products are more stable than the reactants.

2. Positive enthalpy change (ΔH) and negative entropy change (ΔS): Even if the enthalpy change (ΔH) is positive, a negative ΔG can still be achieved if the entropy change (ΔS) is negative and TΔS is greater than ΔH. In this case, the increase in entropy is not sufficient to overcome the increase in enthalpy, and the reaction or process is still spontaneous. This condition is applicable when the increase in disorder is not enough to compensate for the increase in energy.

3. Negative entropy change (ΔS): If the entropy change (ΔS) is negative, it means that the products have a lower disorder or randomness than the reactants. In this case, the reaction or process will decrease the entropy of the system, but if the decrease in enthalpy (ΔH) is greater, the reaction can still be spontaneous, and ΔG will be negative. This condition is applicable when the decrease in disorder is compensated by a larger decrease in energy.

Conclusion:

In summary, the Gibbs free energy change (ΔG) can be negative when the enthalpy change (ΔH) is negative, or the enthalpy change (ΔH) is positive and the entropy change (ΔS) is negative, or the entropy change (ΔS) is negative. Therefore, the correct answer is option 'D' - any of the above conditions can lead to a negative ΔG.