ION-ASSOCIATION REACTION OF H+ AND BR- IN (70, 80, 90 AND 95-MASS PER CENT) 2-BUTANOL-WATER MIXTURES

Molar conductivities of HBr in 70, 80, 90 and 95 mass per cent 2-butanol-water mixtures were measured in the temperature range from 288.15 to 308.15 K at 5 K intervals. The experimental values were analyzed by the conductance equations after Fuoss-Hsia and Lee-Wheaton. Values for the limiting molar conductivity (LAMBDA-o), obtained by both equations, agree well, better than the association constants (K(A)), while the distance parameters (R) differ considerably. Both equations were used to calculate the association constants at different temperatures under the condition that R = q (q is the Bjerrum critical distance). These values were used to obtain standard thermodynamic quantities for the H+ and Br- ion association reaction. The values obtained were compared with the literature data for tert. butanol-water mixtures. The mechanism of H+ ion transfer in the investigated mixtures was also discussed.