Question

Which of the following is not a correct statement?
A.When $\Delta G$ is negative, the process is spontaneous
B.When $\Delta G$ is negative, the process is in state of equilibrium
C.When $\Delta G$ is positive, the process is nonspontaneous
D.None of these

Answer 1

We need to understand what is $\Delta G$ and what is its effect on the process of a chemical reaction. $\Delta G$ is the symbol for change in Gibbs free energy. Gibbs free energy is a thermodynamic potential that may be used to calculate the maximum reversible work that a thermodynamic system can accomplish at constant temperature and pressure.

Complete answer:
Gibbs free energy is the maximum amount of non-expansion work that a thermodynamically closed system may extract (one that can exchange heat and work with its surroundings, but not matter). This limit can only be reached by a totally reversible process. When a system undergoes a reversible transformation from an initial to a final state, the reduction in Gibbs free energy equals the work done by the system to its surroundings, minus the work of the pressure forces.
In a reversible process,
When $\Delta G$ is negative, the process is spontaneous
When $\Delta G$ is zero, the process is in state of equilibrium
When $\Delta G$ is positive, the process is non-spontaneous

Hence, out of the given statements, the incorrect statement is option B.

Note:
It must be noted that exergonic reactions are those that have a negative $\Delta G$ and release free energy. A negative $\Delta G$ indicates that the reactants, or the initial state, have more free energy than the products, or the final state. Exergonic reactions, which can occur without the input of energy, are also known as spontaneous reactions. Reactions with a positive $\Delta G$, on the other hand, need energy input and are referred to as endergonic reactions.