Which of the following does not come under the preview of thermodynamics?

Rate at which a chemical change occurs at a particular set of conditions

The correct answer is option 3. Rate at which a chemical change occurs at a particular set of conditions.

Let us delve into each option and clarify how they relate to either thermodynamics or kinetics:

1. Predicting the feasibility of chemical change:

Thermodynamics is concerned with predicting whether a chemical reaction is spontaneous (feasible) under given conditions. This prediction is based on the change in Gibbs free energy (\(\Delta G\)). If \(\Delta G < 0\), the reaction is spontaneous and feasible. If \(\Delta G > 0\), the reaction is non-spontaneous under the given conditions. If \(\Delta G = 0\), the system is at equilibrium.

2. Predicting the extent of the chemical change:

Thermodynamics also helps in predicting the equilibrium position and the extent to which a reaction will proceed towards completion. This prediction is related to the equilibrium constant (\(K\)), which is determined by the Gibbs free energy change (\(\Delta G\)).

3. Rate at which a chemical change occurs at a particular set of conditions:

Chemical kinetics deals with the rate (speed) at which chemical reactions occur. It focuses on understanding and quantifying the factors that influence reaction rates, such as temperature, concentration, catalysts, and the mechanism of the reaction. Kinetics is concerned with the pathway and speed of reactions rather than whether the reaction will occur (thermodynamics) or how far it will proceed (equilibrium).

4. Effect of temperature on the extent of reaction:

Thermodynamics considers how temperature influences the position of equilibrium and the equilibrium constant (\(K\)). Changes in temperature can shift the equilibrium towards the formation of more products or more reactants, depending on whether the reaction is exothermic or endothermic. Therefore, thermodynamics provides insight into how temperature affects the extent to which a reaction proceeds towards equilibrium.

Conclusion:
Among the options given:

(1) Predicting the feasibility of chemical change and (2) Predicting the extent of the chemical change are within the domain of thermodynamics. They involve understanding the spontaneity and equilibrium conditions of reactions based on energy considerations.

(4) Effect of temperature on the extent of reaction is also related to thermodynamics, as it deals with equilibrium constants and how temperature influences the distribution of products and reactants at equilibrium.

(3) Rate at which a chemical change occurs at a particular set of conditions does not come under the purview of thermodynamics. Instead, it is a topic covered by chemical kinetics, which focuses on reaction rates and the factors influencing them.

Therefore, the concept that does not fall under the purview of thermodynamics is (3) Rate at which a chemical change occurs at a particular set of conditions.