Thorium oxalate is a white insoluble compound of thorium that is prepared by mixing a thorium nitrate solution in acid medium with an oxalic acid solution.
By mixing 0.5 M thorium nitrate solution with 0.5 M oxalic acid solution at room temperature thorium oxalate dihydrate ( Th(C2O4)2.2H2O ) is obtained. Thorium oxalate hexahydrate is obtained when precipitated from 2 M nitric acid solution. On heating to 500° it is converted to thorium oxide. The solubility product (Ksp) of thorium oxalate is 5.01 X 10−25 Density of anhydrous thorium oxalate is 4.637 g/cm3.
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