B. ΔG of the forward and back reactions The free energy of the forward reaction (A → B) is equal in magni- tude but opposite in sign to that of the back reaction (B → A). For example, if ΔG of the forward reaction is −5 kcal/mol, then that of the back reaction is +5 kcal/mol. [Note: ΔG can also be expressed in kilo- joules per mole or kJ/mol (1 kcal = 4.2 kJ).] C. ΔG depends on the concentration of reactants and products The ΔG of the reaction A → B depends on the concentration of the reactant and product. At constant temperature and pressure, the fol- lowing relationship can be derived: ΔG = ∆Go equation. Edit this.

A reaction with a positive ΔGo
can proceed in the forward direction
(have a negative overall ΔG) if the ratio of products to reactants
([B]/[A] ) is sufficiently small (that is, the ratio of reactants to products
is large).