•Can write reactions in general format
•
•  xRSO3- H+  +  Mx+        (RSO3-)x Mx+  +  xH+
•    solid                 solution               solid                    solution
•
•Where R = polymer support (styrene divinylbenzene)
•
•Can write equilibrium expression for exchange
•
•               [(RSO3-)x Mx+]s [H+]xaq
•   Kex  =  -----------------------------       tells affinity of
•                [RSO3- H+]xs [Mx+]xaq        resin for M+
•                                                        compare to H+
•
•                                                                           here or any ion