Conductances of alkali metal chlorides and bromides in aqueous binary mixture of 2-methoxyethanol at 298.15 K

Department of Chemistry, North Bengal University, Darjeeling-734 430, India Fax : 91-0353-581546 Manuscript received 19 August 2002. accepted 12 September 2002 Precise conductance measurements arc reported for alkali metal chlorides and bromides in 2-metboxyetbanol (ME) + water mixture (69.73 ≥ ε ≤ 19.01) at 298.15 Kin the concentration range 0.001-0.08 mol dm-3. The limiting molar conductivity (Ao), the association constant (KA) and the association distance (R) in the solvent mixtures have been evaluated using the Fuoss conductance equation. The single ionic conductances have been evaluated using conductance data for the reference electrolyte Bu4NBPh4. The analysis of our data indicates that the electrolytes are poorly associated in 20, 30 and 40 wt% of ME, whereas in 60, 80, and 90 wt% of ME association is strong. The variation of ionic Walden products with the solvent compositions have been determined and discussed. The limiting ionic conductance (λº±) values for alkali metal ions Ill ow the order : Li+ < Na+ < K+ < Rb+ < Cs+, and for anions : Br- < Cl-. The results have been explained in terms of ion-solvent interactions and structural changes in the mixed solvents