Question

Which quantity out of ${{\Delta }_{r}}G$ and ${{\Delta }_{r}}{{G}^{\ominus }}~$ will be zero at equilibrium?

Answer 1

Gibbs free energy, also known as Gibbs function, Gibbs energy, or free enthalpy, is a number used to measure the greatest amount of work done in a thermodynamic system while temperature and pressure remain constant. The letter ‘G' stands for Gibbs free energy. Its energy is often measured in Joules or Kilojoules. The greatest amount of work that may be taken from a closed system is defined as Gibbs free energy.

Complete answer:
Gibbs free energy is equal to the system's enthalpy minus the temperature and entropy product. The equation is as follows:
G = H – TS
Where,
G = Gibbs free energy
H = enthalpy
T = temperature
S = entropy
Because Gibbs free energy is a state function, it is independent of the route. As a result, the change in Gibbs free energy equals the change in enthalpy minus the product of the system's temperature and entropy change.
Entropy in the cosmos constantly rises for a spontaneous process, according to the second rule of thermodynamics.
The direction and extent of chemical change are determined by G.
Only reactions in which the temperature and pressure stay constant are relevant to G. We start and complete the operation at room temperature, and the system is generally exposed to the environment (constant pressure) (after any heat we have added or which is liberated by the reaction has dissipated).
The criteria for $A+B\rightleftharpoons C+D$ ; equilibrium is ${{\Delta }_{r}}G=0$
Gibbs energy is linked to the equilibrium constant of a process in which all reactants and products are in a standard condition as follows: $0={{\Delta }_{r}}{{G}^{\Theta }}+RTlnK$ .

Note:
G is the one master variable that determines whether a certain chemical change is thermodynamically feasible. As a result, if the reactants' free energy is larger than the products', the world's entropy will rise when the reaction occurs as described, and the process will tend to occur spontaneously.