Plutonium hydrolysis and the double double-point

Abstract

There is uncertainty about the numerical value of the first hydrolysis constant of the tetravalent plutonium ion. A new method for discriminating between the claims is illustrated. It suggests the traditional estimates of that constant are closer to its true value than a singular result based on a few solvent extraction experiments. A previously unnoticed multiple point in aqueous Pu chemistry is illustrated.

Nonequilibrium method for estimating the first hydrolysis constant of tetravalent plutonium

“…The traditional estimates ofK H are about 0.02-0.05 . Recent analyses of the distributions of the four oxidation states of plutonium have been used to estimate its numerical value [1][2][3][4][5][6]. The recent results reinforce the traditional estimates of K H .…”

“…The estimated properties of soluble plutonium at triple points are summarized in because the triple points appear to be easier to realize experimentally [6].…”

“…This sensitivity appears to be sufficient to differentiate between the traditional estimates of KH and the singular number obtained by solvent extraction experiments [7]. An earlier presentation cited two plutonium triple points [6]. The reference is to the two principal triple points that occur at the intersections of boundary lines in predominance-region diagrams [10].…”