Ionic Size Effect on Equilibrium Constant for Some Uni-Bivalent Exchange Reactions

Abstract

Ion exchange resins Amberlite IRA-400 in chloride and iodide
form were equilibriated respectively with oxalate and sulphate ion
solution of seven different concentrations from 0.010 M to 0.050
M in the temperature range of 30 to 45°C. The equilibrium constant
(K) values calculated for both Cl^-/C₂O₄^2-  and  I^-/SO₄^2-  uni-bivalent
exchange increases with increase in temperature. The K value at 30°C
for Cl^-/C₂O₄^2-  ion exchange was calculated to be 19.5 which was
higher than 0.250 for  I^-/SO₄^2-  exchange at same temperature. The
variation in values of K was due to the difference in ionic size of
exchangeable oxalate and sulphate ions in solution.