The object of this book is the presentation of the above important facts and theories relating to the different potentials of electrolyte. This work is aimed at M.Sc. students and research scholars working in this field and who are familiar with the basics of thermodynamics. The true precipitation & dissolution potential of electrolytes have been distinguished from the observed one. Reader who desire additional background material can readily find it in the references given here. Experimental data have been analysed in the light of the theories given in this book. I have however tried to give a broad coverage of the field. I wish to express my sincere thanks to the Head, Dept. of Chemistry, University of Gorakhpur, India and the Principal St. Andrews College, Gorakhpur for providing necessary facilities. I wish to express my sense of obligation to my wife and children for their cooperation during the entire course of this work. Above all, I also feel it a divine help and celestial inspiration for which I bow my head to the Almighty. Dr.B.N.Tripathi