Kinetics of Reduction of Np(V)by Hydroxylammonium Chloride in Perchloric Acid Solution

Abstract

The kinetics of the reaction between Np (V) and hydroxylammonium chloride in perchloric acid solution was studied at 70°c. In perchloric acid solutions from 1.0 to 1.5 mol·dm⁻³, the reaction rate is described by

−d[Np(V)]/dt = k{Np(V)][NH₃OHCl]^1.0[H⁺]^2.1

where the rate constant k = (6.7 ± 0.3) × 10⁻² mol^−3.7dm^11.1min⁻¹. Detailed studies of the dependence of the rate on the concentrations of hydroxylammonium ion and chloride ion showed that the reaction is much accelerated by chloride ion.

KEYWORDS:

• actinoid
• chloride ions
• hydroxylamine
• hydroxylammonium chloride
• neptunium
• neptunyl ions
• Purex process
• reaction kinetics
• redox reaction