Equilibria in Acetic Acid: Ion Association Constants of Salts and the Autoprotolysis Constant of Acetic Acid at 105.7°C

Abstract

The ion association constants K_A=[M⁺A^-]/[M⁺][A^-] which have been measured conductimetrically at 105 7 °C in acetic acid are : perchloric acid 0.0644 X 10⁶, sodium perchlorate 0.1346 x 10⁶, and sodium acetate 0.752 x 10⁶. The parameters 6, centre to centre distance between the ions at contact, which were calculated from Bjerrum's formula, are : perchloric acid 4.52 Ǻ, sodium perchlorate 4.20 Ǻ, and sodium acetate 3.61 Ǻ. The autoprotolysis constant, K = [H₂⁺ Ac][Ac^-]= 1.17 x 10^-19, was calculated from the specific conductivity of acetic acid at 105.7 °C. The acetic acidium acetate ion pairs were calculated to be 100.0% dissociated.