Thermodynamic studies of ion-exchange equilibria of some bivalent metal ions with H+ on stannic arsenate cation exchanger

Abstract

Ion-exchange equilibria of Ba²⁺, Sr²⁺, Ca²⁺, Mg²⁺, Mn²⁺ and Zn⁺with H⁺ have been studied at 288, 298, 313 and 333 K on stannic arsenate cation exchanger at constant ionic strength. The ion-exchange isotherms have been plotted for both forward and backward reactions by batch technique. The selectivity coefficient and various thermodynamic parameters, i.e., standard free energy change, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>G</em>ᵒ, enthalpy change, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>H</em>ᵒ, and entropy change, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>S</em>ᵒ, of the systems have been calculated.