What kind of energy change occurs in a spontaneous process?

• A. Positive ΔG
• B. Negative ΔG
• C. No change in energy
• D. Neutral energy

Answer: (B)

In a spontaneous process, the change in Gibbs free energy (ΔG) is negative. This indicates that the process can occur without the input of external energy. A negative ΔG suggests that the products of the reaction have lower free energy than the reactants, making the reaction energetically favorable.

Spontaneous processes are characterized by the tendency to proceed towards a state of lower energy and increased disorder (entropy), aligning with the second law of thermodynamics. This energy change reflects the natural tendency of systems to evolve toward equilibrium, where free energy is minimized.

When ΔG is negative, it is associated with exergonic reactions, which release energy, often in the form of heat or work. In contrast, if ΔG were positive, it would indicate that the process is non-spontaneous and requires energy input to occur. Therefore, in the context of spontaneous processes, a negative ΔG is a clear indicator of the energy changes involved.