Which of the following is a condition for a spontaneous reaction?

Answer Details

The condition for a spontaneous reaction is that the Gibbs free energy change (∆G) of the system should be negative. ∆G is related to enthalpy change (∆H), entropy change (∆S), and temperature (T) through the equation:
∆G = ∆H - T∆S
For a spontaneous reaction, ∆G must be negative, which can only occur when one of the following conditions is met:
- ∆H is negative (exothermic reaction) and ∆S is positive (increase in disorder)
- ∆H is positive (endothermic reaction) and ∆S is negative (decrease in disorder), but T∆S is larger than ∆H, so the overall ∆G is negative.
Therefore, the option that represents a condition for a spontaneous reaction is: ∆H-T∆S is negative.