Pravin U. Singare, Akmal L. Khan Mohammed, N.N. Dixit, Study on Preferential Selectivity of Nuclear Grade Resin Indion-223 towards some Bivalent Ions, ILCPA Volume 34, International Letters of Chemistry, Physics and Astronomy (Volume 34)
    In the present paper attempts are made to understand the selectivity of nuclear grade cation exchange resin Indion-223 in H<sup>+</sup> form towards Ca<sup>2+</sup> and Mg<sup>2+</sup> bivalent ions in the solution based on thermodynamic concept. It was observed that with rise in temperature the equilibrium constant<i> K</i> values for H<sup>+</sup>/Ca<sup>2+</sup> uni-bivalet ion exchange reactions increases from 0.000397 to 0.000639. Similarly for H<sup>+</sup>/Mg<sup>2+</sup> uni-bivalet ion exchange reactions the equilibrium constant <i>K</i> values increases from 0.000177 to 0.000333. The increase in equilibrium constant values with rise in temperature indicate endothermic ion exchange reactions having the enthalpy change values of 38.92 and 51.46 kJ/ mol respectively. The difference in K values and enthalpy values were used to predict the selectivity behaviour of the resin towards the Ca<sup>2+</sup> and Mg<sup>2+</sup> bivalent ions in the solution. The thermodynamic concept of the present study can be applied to understand the selectivity behaviour of different nuclear as well as non-nuclear grade resins towards wide range of ionic species present in the exchanging liquid medium.
    Bivalent Exchange Reactions, Cation Exchange, Enthalpy Change, Equilibrium Constant, Indion-223, Ionic Selectivity, Nuclear Grade Resins, Reaction Thermodynamics