Calculation of Ionic Activity and Ion pairs by Using Excel 2010 Program for Some Calcareous and Gypsum Soils

Abstract

To express accurately the chemistry ions in the soil - water system has to be used some thermodynamic concepts in this area and it has been calculated activity and ion pairs by using Excel 2010 for Some calcareous and gypsum soils In general the results indicate:--The sequence of ion activity was found as follows :-Na+ >SO4-2 > Ca+2 > Mg+2> HCO3- > K+ > H2PO4-And the concentration of ion pairs was in the following order:-(CaSO4)0 > (MgSO4)0 > (NaSO4)- > (MgHCO3)+ > (CaHCO3)+ > (KSO4)- > (CaH2PO4)+ Also the concentration of the free ions was in the following order:- Na+ > SO4-2 > Ca+2 > Mg+2 > HCO3- > K+ > H2PO4- Noting that dominant of sodium Ion due to less ion pairs formation.