SIMULASI KESEIMBANGAN PERTUKARAN KATION Na', K+, Me, dan Ca2+ DALAM RESIN PENUKAR KATION DOWEX 50W-X8 (Simulation of Ion Exchange Equilibria for Na+, K', me, and Cat' Cations in the Dowex 50W-X8 Cation-Exchanger Resin)

ABSTRACT Ion exchange equilibria for Na+, K4, Mg', and Ca2+ cations in cation exchanger resin Dowex 50W-X8 have been studied by varying the concentration of hydrochloric acid as solvent, volume and concentration of the solution. The effect of other ions on analyte was observed by determining the distribution coefficient of the corresponding ions by which the separable ions might be predicted. The result of the study indicated that the increase in concentration of hydrochloric acid solvent decreased the distribution coefficient of ion and the effect was more pronounce to ions having +2 charge than those bearing +1 charge. Volume and concentration of the solution also affected other ions. Addition of Ca' ion 5 times higher than the concentration of the reference ion in the solution, decreased the distribution coefficient of reference Na' ion from 210 to 18, and of Mg' reference ion from 495 to 79, respectively. The separation factor might be adjusted by variying the concentration of the solvent, volume and concentration of the solution by adding another ion which had similar properties to that of the analyte in the sample. Therefore, it was considered to be unexact to determine the distribution coefficient of each ion individually from the standard solution used as reference for separation. Keywords: equilibria, cation exchange, distribution coefficient, separation facto