Question

What is delta G in thermodynamics?

Answer 1

1. $∆\mathrm{G}$ in thermodynamics denotes the change in Gibbs Free energy of a chemical reaction.
2. Gibbs free energy is the amount of total energy present in a thermodynamic system that is used in doing work.
3. Gibbs free energy is a state function hence it does not depend on the path of reaction.
4. Change in Gibbs free energy is equal to the difference in change in enthalpy $∆\mathrm{H}$ and product of temperature$\mathrm{T}$ and change in entropy $∆\mathrm{S}$of a system. $∆\mathrm{G}=∆\mathrm{H}-\mathrm{T}∆\mathrm{S}$
5. The above equation is known as Gibbs Helmholtz equation.
6. If the value of $$\begin{gathered} ∆\mathrm{G}>0,\mathrm{the}\mathrm{reaction}\mathrm{is}\mathrm{non}-\mathrm{spontaneous}\mathrm{and}\mathrm{endergonic} \\ ∆\mathrm{G}<0,\mathrm{the}\mathrm{reaction}\mathrm{is}\mathrm{spontaneous}\mathrm{and}\mathrm{exergonic} \\ ∆\mathrm{G}=0,\mathrm{reaction}\mathrm{is}\mathrm{at}\mathrm{equilibrium}. \end{gathered}$$