Determination of equilibrium constant of Cl-/I- and Cl-/C2O42- ion exchange reaction was carried out in the temperature range of 30-45 degreesC, by varying the concentration of iodide and oxalate ion solution. It was observed that under identical conditions of temperature 30 degreesC, using 0.5 g of ion exchange resin (in chloride form), the equilibrium constant (K) for Cl-/I- exchange was 16.7 which was lesser than 19.5 for Cl-/C2O42- exchange. Also for both uni-univalent and uni-bivalent exchange, value of K increases with increase in temperature, indicating the endothermic ion exchange reaction with enthalpy values of 19.13 kJ/mole and 12.2 kJ/mole respectively.