Electrical conductances of sodium bromide and sodium tetraphenylborate in 2-ethoxyethanol + water mixtures at 308.15, 313.15, 318.15 and 323.15 K

The electrical conductances of the solutions of sodium bromide (NaBr) and sodium tetraphenylborate (NaBPh4) in 2-ethoxyethanol + water mixed solvent media containing 0.25, 0.50 and 0.75 mass fractions of 2-ethoxyethanol (w1) have been reported at 308.15, 313.15, 318.15, and 323.15 K. The conductance data have been analyzed by the 1978 Fuoss conductance-concentration equation in terms of the limiting molar conductance (Λ0), the association constant (KA) and the association diameter (R). Of the two electrolytes investigated here, sodium bromide exists essentially in the form of free ions in aqueous 2-ethoxyethanol solutions over the entire temperature range investigated. However, slight ionic association was observed for sodium tetraphenylborate-the extent of which increases with increasing amount of 2-ethoxyethanol in the present mixed solvent media. The solvations of the bromide ion and of the sodium ion were found to be gradually weakened as the 2-ethoxyethanol content of the medium increases. Furthermore, the limiting molar conductivity values of the two electrolytes increase as the temperature increases in all 2-ethoxyethanol + water mixtures which have been described by polynomial equations.