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Kinetics of the reaction between plutonium (4) and neptunium (4) in nitric acid solution

Journal Article:

Abstract

The kinetics of the oxidation of neptunium(IV) to neptunium(V) by tetravalent plutonium ions in solutions of HNO/sub 3/ + NaNO/sub 3/ at constant (..mu.. = 2) and variable (..mu.. = 0.7-2.0) ionic strengths of the solution was investigated by a spectrophotometric method. It was established that in the range of concentrations (Np(IV)) = (4.25-10.6) x 10/sup 13/; (Pu(IV)) = (2.6-3.9)x10/sup -3/ M; (H/sup +/) 0.37-1.91 M, a first order is observed with respect to the reagents, while the order of the reaction with respect to H/sup +/ ions is equal to -3. The average value of the true rate constant of the reaction is k = 27.9+-1.3 M/sup 2/xmin/sup -1/ at ..mu..=2 and 39/sup 0/C. It was shown that with increasing analytical concentration of HNO/sub 3/ and NO/sub 3//sup -/ ions (in a mixture of HNO/sub 3/ +HClO/sub 4/), the value of K decreases. On the basis of an invetigation of the dependence of the reaction rate on the temperature in the interval 31-44.8/sup 0/, we calculated the values of the energy (E = 34.6 kcal/mole), enthalpy (..delta..H* = 34 kcal/mole), free energy (..delta..F* = 19.6 kcal/mole, entropy (..delta..S* = 49 entropy units) of activation of the reaction and the  More>>
Publication Date:
Jan 01, 1976
Product Type:
Journal Article
Reference Number:
AIX-08-342844; EDB-78-038965
Resource Relation:
Journal Name: Radiokhimiya; (USSR); Journal Volume: 18:2
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; NEPTUNIUM; CHEMICAL REACTION KINETICS; PLUTONIUM; COMPARATIVE EVALUATIONS; COMPLEXES; ENTROPY; MEDIUM TEMPERATURE; NEPTUNIUM COMPOUNDS; NITRATES; NITRIC ACID; PH VALUE; PLUTONIUM COMPOUNDS; QUANTITY RATIO; ACTINIDE COMPOUNDS; ACTINIDES; ELEMENTS; HYDROGEN COMPOUNDS; INORGANIC ACIDS; KINETICS; METALS; NITROGEN COMPOUNDS; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; REACTION KINETICS; THERMODYNAMIC PROPERTIES; TRANSURANIUM COMPOUNDS; TRANSURANIUM ELEMENTS; 400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
OSTI ID:
5240666
Country of Origin:
USSR
Language:
Russian
Other Identifying Numbers:
Journal ID: CODEN: RADKA
Submitting Site:
INIS
Size:
Pages: 264-269
Announcement Date:

Journal Article:

Citation Formats

Koltunov, V S, Zhuravleva, G I, and Marchenko, V I. Kinetics of the reaction between plutonium (4) and neptunium (4) in nitric acid solution. USSR: N. p., 1976. Web.
Koltunov, V S, Zhuravleva, G I, & Marchenko, V I. Kinetics of the reaction between plutonium (4) and neptunium (4) in nitric acid solution. USSR.
Koltunov, V S, Zhuravleva, G I, and Marchenko, V I. 1976. "Kinetics of the reaction between plutonium (4) and neptunium (4) in nitric acid solution." USSR.
@misc{etde_5240666,
title = {Kinetics of the reaction between plutonium (4) and neptunium (4) in nitric acid solution}
author = {Koltunov, V S, Zhuravleva, G I, and Marchenko, V I}
abstractNote = {The kinetics of the oxidation of neptunium(IV) to neptunium(V) by tetravalent plutonium ions in solutions of HNO/sub 3/ + NaNO/sub 3/ at constant (..mu.. = 2) and variable (..mu.. = 0.7-2.0) ionic strengths of the solution was investigated by a spectrophotometric method. It was established that in the range of concentrations (Np(IV)) = (4.25-10.6) x 10/sup 13/; (Pu(IV)) = (2.6-3.9)x10/sup -3/ M; (H/sup +/) 0.37-1.91 M, a first order is observed with respect to the reagents, while the order of the reaction with respect to H/sup +/ ions is equal to -3. The average value of the true rate constant of the reaction is k = 27.9+-1.3 M/sup 2/xmin/sup -1/ at ..mu..=2 and 39/sup 0/C. It was shown that with increasing analytical concentration of HNO/sub 3/ and NO/sub 3//sup -/ ions (in a mixture of HNO/sub 3/ +HClO/sub 4/), the value of K decreases. On the basis of an invetigation of the dependence of the reaction rate on the temperature in the interval 31-44.8/sup 0/, we calculated the values of the energy (E = 34.6 kcal/mole), enthalpy (..delta..H* = 34 kcal/mole), free energy (..delta..F* = 19.6 kcal/mole, entropy (..delta..S* = 49 entropy units) of activation of the reaction and the formal ionic entropy of the activated complex (PuOOHNp/sup 5 +/)*, S* = -87 entropy units. A reaction mechanism including an interaction of hydrolyzed neptunium and plutonium ions as the rate-determining step was proposed and discusses. The results obtained are compared with data for this reaction in perchloric acid wolution and for other similar redox reactions.}
journal = {Radiokhimiya; (USSR)}
volume = {18:2}
journal type = {AC}
place = {USSR}
year = {1976}
month = {Jan}
}