Conductance measurements on solutions of salts in sulpholane and their interpretation

Precise conductance measurements have been made on twelve uni-univalent salts dissolved in sulpholane. The results have been fitted to better than 0.1 % by introducing an association constant and by using the Pitts equation for the conductance of free ions. To reconcile the closest distances of approach of associated ions according to the Bjerrum model with the sums of ionic radii it is necessary to take account of dielectric saturation. This is particularly so for lithium chloride and bromid which have association constants of 1.386 × 104 l. mole–1 and of 278 l. mole–1 respectively.