Question

At chemical equilibrium, the:
(A) Enthalpy of system Is minimum
(B) entropy of system Is maximum
(C) free energy of system is minimum
(D) free energy of system is 0

Answer 1

Hint :Chemical equilibrium is the condition of a chemical process in which both the reactants and products are present in concentrations that have no further tendency to vary with time, resulting in no apparent change in the system's attributes.

Complete Step By Step Answer:
Chemical equilibrium is a state in which no net change in the quantities of reactants and products occurs during a reversible chemical process. A reversible chemical reaction occurs when the products react with the original reactants as soon as they are generated. There is no net change in the quantity of chemicals involved when the two opposing reactions occur at identical rates, or velocities. At this point, the reaction can be called complete; that is, the maximal conversion of reactants to products has been achieved for a given reaction setting. Because the system has zero free energy at equilibrium, the reaction seems to be static. As the reaction approaches equilibrium, the system's enthalpy lowers and becomes lowest. Any external factor that disrupts the equilibrium of the system by causing a change in pressure, temperature, or volume shifts the system toward the direction where the enthalpy of combustion is highest. The system will be simple and straightforward. The maximum entropy may be found in any system that is in equilibrium. Enthalpy/energy diminishes as entropy rises.
Hence option A, C, D are correct.

Note :
At constant temperature and pressure, the Gibbs free energy, G, must be considered, whereas at constant temperature and volume, the Helmholtz free energy, A, must be considered; and at constant internal energy and volume, the entropy, S, must be considered. In geochemistry and atmospheric chemistry, where pressure changes are substantial, the constant volume case is crucial. There would be no reversibility or equilibrium if the reactants and products were in their standard condition (totally pure).