What does the symbol ∆G represent in thermodynamics?

The symbol ∆G represents the change in Gibbs free energy, which is a crucial concept in thermodynamics and chemical reactions. Gibbs free energy is a thermodynamic potential that helps predict the direction of chemical processes and the spontaneity of reactions under constant temperature and pressure conditions.

When the value of ∆G is negative, it indicates that a reaction is spontaneous, meaning it can occur without any external input of energy. Conversely, a positive ∆G suggests that the reaction is non-spontaneous, and energy input is required to drive it forward.

In addition, ∆G is related to the enthalpy (∆H) and entropy (∆S) of the system through the equation:

∆G = ∆H - T∆S

where T is the temperature in Kelvin. This relationship highlights how both energy changes and disorder can influence the feasibility of a reaction.

The other options do not accurately define ∆G. The total energy of the system, the equilibrium constant, and the enthalpy change represent different aspects of thermodynamic systems and reactions, but they do not encompass the specific changes in free energy that ∆G indicates. Hence, the emphasis on Gibbs free energy makes the correct understanding of ∆G