Plutonyl sulfate

Pu(N03 ) -5H2 0 deep red plutonyl nitrate hexahydrate [19125-90-7], Pu02(N03 )2-6H2 0 coral red anhydrous plutonium(IV) sulfate [13692-89-2], Pu(S0 2i pinh or redPu(S0 2 4H20 and moss green plutonyl carbonate/ P2P2-/(9-P/, PUO2CO2 (30). 

In contrast, the solubilities of the neptunyl species were increased by HEDTA and unexpectedly decreased by EDTA. Plutonyl(V) solubility was not affected by HEDTA or EDTA. The component most significant to neptunium solubility was NaNOz. Sodium nitrite apparently decreased neptunium solubility by reducing the more soluble neptunyl(VI) to the less soluble (V) state. The existence of two oxidation states complicated interpretation of the neptunium data. Sodium carbonate, phosphate, aluminate, and sulfate all increased neptunium solubility, probably through complexation. Separation of the data... 

Carbonate Complexes. Of the many ligands which are known to complex plutonium, only those of primary environmental concern, that is, carbonate, sulfate, fluoride, chloride, nitrate, phosphate, citrate, tributyl phosphate (TBP), and ethylenediaminetet-raacetic acid (EDTA), will be discussed. Of these, none is more important in natural systems than carbonate, but data on its reactions with plutonium are meager, primarily because of competitive hydrolysis at the low acidities that must be used. No stability constants have been published on the carbonate complexes of plutonium(III) and plutonyl(V), and the data for the plutoni-um(IV) species are not credible. Results from studies on the solubility of plutonium(IV) oxalate in K2CO3 solutions of various concentrations have been interpreted to indicate the existence of complexes as high as Pu(C03) , a species that is most unlikely from both electrostatic and steric considerations. From the influence of K2CO3 concentration on the solubility of PuCOH) at an ionic strength of 10 M, the stability constant of the complex Pu(C03) was calculated (10) to be 9.1 X 10 at 20°. This value... 

Numerous determinations have been made of the stability constants of sulfate complexes of plutonium(IV), and the results vary by three orders of magnitude. The most plausible values (14) have come from careful ion exchange studies at I = 2 M and 25°, which indicate the presence of two species, Pu(S0i+) and Pu(S0i )2, with stepwise stability constants of 6.6 X 10 and 5.8 X 10, respectively. This Ki is in satisfactory agreement with the value 4.6 X 10 obtained potentiometrically at I = 1 M and 25° ( ). Spectrophotometric and electrophoretic studies indicate that plutonyl(VI) forms complexes containing as many as four sulfate groups, with anionic species predominating at sulfate concentrations above 1 M (15). The monosulfato complex has a reported stability constant of 14.4 as determined by extraction studies at I - 2 M and 25° (16). 

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