What occurs when Delta S is negative and Delta H is negative?

When the change in entropy (Delta S) is negative and the change in enthalpy (Delta H) is also negative, the process exhibits specific thermodynamic characteristics. A negative Delta H indicates that the reaction is exothermic, meaning it releases heat. A negative Delta S suggests a decrease in randomness or disorder in the system.

According to Gibbs Free Energy (G), which determines the spontaneity of a process, the relationship can be defined by the equation:

G = Delta H - T * Delta S

In this equation, T represents temperature in Kelvin. For the process to be spontaneous, G must be negative. Given that both Delta H is negative and Delta S is negative, the behavior of the Gibbs Free Energy depends on the temperature. As the temperature increases, the term T * Delta S becomes more negative.

At lower temperatures, the negative Delta H (which favors spontaneity) outweighs the effect of the negative T * Delta S (which opposes spontaneity). Therefore, the process is spontaneous at low temperatures where the exothermic nature dominates. As temperature increases, the influence of the negative entropy becomes significant, leading to non-spontaneous behavior at higher temperatures.

Thus, the correct conclusion is that the process is