Electrical conductivity of aqueous solutions and the hydrolysis constant of hydroxylamine hydrochloride in the temperature range 0-50°C

The electrical conductivity of aqueous solutions of hydroxylamine hydrochloride was studied in the concentration and temperature ranges 0.00025-0.1 mol/l and 0-50 degrees C, respectively. In the absence of a platinum electrode (in the absence of current) and oxygen dissolved in water, dilute solutions of the salt were catalytically oxidized with the formation of an uncharged nitrogen compound (presumably N-2) a method for measuring conductivity of such solutions was developed. The conductivity equation for solutions of hydrolyzable salts was used to calculate the limiting conductivity (Lambda(0)) and the hydrolysis constant (K-h) of hydroxylamine hydrochloride from the results of conductivity measurements. The limiting conductivity of the hydroxylaminium ion (lambda(0)) at 25 degrees C was found to be 49.27 +/- 0.17 Ohm(-1) cm(2) g-equiv(-1) and its temperature dependence was correctly described by the Jonston equation. The standard thermodynamic functions of formation of hydroxylamine hydrate and the NH3OH+ ion in aqueous solutions were calculated. Possible mechanisms of catalytic oxidation of hydroxylamine in acid solutions were considered.