Thorium-230, extraction derivatives

The concentration of the dissolution medium was not specified and apparently, only one experiment was reported (0.8925 g Th(S04)2 reacted with 500 cm of solution). The lack of proper identity of the thorium hydroxide precipitate resulting from the reaction adds to the difficulty in extracting meaningful conclusions from this experiment. In a quite unclear way Beck [1928BEC] derives from his experimental result a value of -483.3 kJ-mok for the enthalpy of the reaction Th02(cr) + 2SO3 Th(S04)2(cr), at 291.15 K. The physical state of SO3 to which this value applies is not stated, but is most probably gaseous. 

Thiophen Derivatives of Analytical Interest.—2-Thenoyltrifluoroacetone has maintained its position as a chelating agent in analytical chemistry. Papers describing its use in the extraction or determination of thorium, copper, europium, thallium, niobium, and molybdenum have appeared. The effect of copper(n) on the formation of monothenoyltri-fluoroacetonatoiron(iii) has been studied. The stability constants of some bivalent metal chelates of di-(2-thenoyl)methane have been determined. 3-Thianaphthenoyltrifluoroacetone has been proposed as a reagent for the spectrophotometric determination of iron(iii) and cerium(iv). The stabilities of metal chelates formed from derivatives of thiophen-2-aldehyde and of rare-earth carboxylates of thiophen-2-carboxylate have been studied. 

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