Question

Calculate the Gibbs free energy change for the following electrochemical reaction at 298 K:2Fe³⁺(aq) + 2e⁻ → 2Fe²⁺(aq)Given that the standard Gibbs energy of formation of Fe³⁺(aq) is -290.5 kJ/mol and that of Fe²⁺(aq) is -91.2 kJ/mol.

Answer 1

To calculate the Gibbs free energy change  G  for the given electrochemical reaction, we can use the following equation:G = G products  - G reactants For the given reaction:2Fe aq  + 2e  2Fe aq The reactants are 2 moles of Fe aq  and the products are 2 moles of Fe aq . We are given the standard Gibbs energy of formation for both Fe aq  and Fe aq . First, we need to multiply the standard Gibbs energy of formation of each species by their stoichiometric coefficients:G reactants  = 2 *  -290.5 kJ/mol  = -581.0 kJ/molG products  = 2 *  -91.2 kJ/mol  = -182.4 kJ/molNow, we can use the equation to find the Gibbs free energy change for the reaction:G = G products  - G reactants G =  -182.4 kJ/mol  -  -581.0 kJ/mol G = 398.6 kJ/molSo, the Gibbs free energy change for the given electrochemical reaction at 298 K is 398.6 kJ/mol.