question_answer 101)

  What is the relationship between Gibbs free energy of the cell reaction in a galvanic cell and the emf of the cell? When will the maximum work be obtained from a galvanic cell?  

Answer:

                    If concentration of all reacting species is unity, then and Where,  is standard Gibbs energy of the reaction                        = emf of the ce11                        nF = charge passed If we want to obtain maximum work from a galvanic cell then charge has to be passed reversibly. The reversibly work done by a galvanic cell is equal to decrease in its Gibbs energy.                         As  is an intensive parameter but A,. G is an extensive thermodynamic property and the value depends on n. For reaction,  in a galvanic cell.                                  [Here, n = 2]