Introducing the application of free energy correlations to elucidating the mechanisms of organic and bio-organic reactions, this book provides a new and illuminating way of approaching a potentially complex topic. The idea of how free energy correlations derive from polar substituent change is introduced, and common pitfalls encountered in the application of free energy relationships are described, along with the use of these anomalies in mechanistic studies. The concept of effective charge is described in detail, with examples of its application. Throughout, worked answers are provided for the problems posed. Databases of parameters, an extensive bibliography and comprehensive lists of further reading are also included. The text provides an invaluable source of information to senior undergraduates, postgraduates and to industrial researchers with an interest in mechanistic studies. It is the first such book in more than thirty years. ... where would a mechanistic, physical or even a synthetic organic chemist go to become more fluent in the use of free energy relationships? What a good resource when we teach this material to undergraduate and graduate students? I believe the answer to both questions is Free Energy Relationships in Organic and Bio-Organic Chemistry ... The book would be a nice supplement to a larger tome used in a senior or graduate level course in organic or physical organic chemistry. It would be an excellent textbook for a specialty course in free energy relationships. Free Energy Relationships; The Equations; Effective Charge; Multiple Interactions to the Reaction Centre; Anomalies and Special Cases; Coupling Between Bonds in Transition States of Displacement Reactions; Applications; Answers to Problems; Summary of Equations; Tables of Constants; Some Linear Free Energy Equations.The text provides an invaluable source of information to senior undergraduates, postgraduates and to industrial researchers with an interest in mechanistic studies.