How can the standard Gibbs energy of reaction be expressed in terms of standard Gibbs energies of formation?

The standard Gibbs energy of reaction is related to the standard Gibbs energies of formation of the reactants and products involved in the reaction. The expression provided states that the standard Gibbs energy change for a reaction can be calculated by taking the sum of the standard Gibbs energies of formation of the products, each multiplied by their respective stoichiometric coefficients (ν), and subtracting the sum of the standard Gibbs energies of formation of the reactants, also weighted by their stoichiometric coefficients.

This formulation is grounded in the fact that the Gibbs energy of formation (ΔfG°) represents the energy change associated with forming one mole of a compound from its elements in their standard states. Thus, when a reaction occurs, it can be viewed as a transformation in which certain amounts of reactants are converted into products, and the Gibbs energies of formation tally the energy changes for those transformations.

Therefore, by summing these Gibbs energies with the appropriate coefficients, you effectively compile the total energy change associated with going from the reactants to the products, which is precisely what the standard Gibbs energy of the reaction (Δ_rG°) represents. In essence, this connection allows for the calculation of the reaction's thermodynamic favorability, as governed by the differences in Gibbs energy