Lanthanide iodides solubility

The chlorides, bromides, nitrates, bromates, and perchlorate salts ate soluble in water and, when the aqueous solutions evaporate, precipitate as hydrated crystalline salts. The acetates, iodates, and iodides ate somewhat less soluble. The sulfates ate sparingly soluble and ate unique in that they have a negative solubitity trend with increasing temperature. The oxides, sulfides, fluorides, carbonates, oxalates, and phosphates ate insoluble in water. The oxalate, which is important in the recovery of lanthanides from solutions, can be calcined directly to the oxide. This procedure is used both in analytical and industrial apptications. 

The triiodides are slightly more soluble in water than the tribromides [Table XXI (269-276)] the published value for samarium triiodide looks suspiciously high. The addition of hydrogen iodide produces a large decrease in the solubility of yttrium triiodide, from 66.98 wt % in water to 4.90 wt % in 63.45 wt % HI (in both cases at 0°C) (269). Other lanthanide triiodides behave similarly (272-274). 

As a rule, lanthanide bromides, and more especially the iodides, are more reactive because of their often higher solubility (Table 5), and also show enhanced thermodynamic lability (Scheme III). Moreover, reactivities different from those of the chloride analogues should be expected because of, for example, the softer Lewis basicity of the iodide anion and different solubility properties of the eliminated alkali salts. Table 5 gives an arbitrary sample of solubilities for lanthanide halides in various standard-laboratory donating solvents [97f]. 

Most ionic halides dissolve in water to give hydrated metal ions and halide ions. However, the lanthanide and actinide elements in the +3 and +4 oxidation states form fluorides insoluble in water. Fluorides of Li, Ca, Sr, and Ba also are sparingly soluble, the lithium compound being precipitated by ammonium fluoride. Lead gives a sparingly soluble salt PbCIF, which can be used for gravimetric determination of F . The chlorides, bromides, and iodides of Ag1, Cu1, Hg1, and Pbn are also quite insoluble. The solubility through a series of mainly ionic halides of a... 

Neodymium oxide was first isolated from a mixture of oxides called didymia. The elemeut ueodymium is the secoud most abuudaut lanthanide elemeut in the igneous rocks of Earth s crust. Hydrated neodymium(III) salts are reddish and anhydrous neodymium compounds are blue. The compounds neodymium(III) chloride, bromide, iodide, nitrate, perchlorate, and acetate are very soluble neodymium sulfate is somewhat soluble the fluoride, hydroxide, oxide, carbonate, oxalate, and phosphate compoimds are insoluble. 

Cm(iii) is a class A or hard metal ion and thus complexes far more strongly to oxygen and fluoride donors than to more polarizable donors such as chloride or sulfur. Solution reactions of Cm resemble those of the trivalent lanthanides and actinides. The fluoride, oxalate, phosphate, iodate, and hydroxide are essentially water-insoluble and the chloride, iodide, perchlorate, nitrate, and sulfate are water-soluble. The first hydrolysis constant for Cm ", i.e. for the reaction ... 

The actinide ions in aqueous solution resemble the tripositive lanthanide ions in their precipitation reactions, allowing for differences in the redox properties of early members of the actinide series. The chloride, bromide, nitrate, bromate, and perchlorate anions form water-soluble salts, which can be isolated as hydrated solids by evaporation. The acetates, iodates, and iodides are somewhat less soluble in water. The sulfates are sparingly soluble in hot solutions, somewhat more soluble in the cold. Insoluble precipitates are formed with hydroxide, fluoride, carbonate, oxalate, and phosphate anions. Precipitates formed from aqueous solution are usually hydrated, and the preparation of anhydrous salts from the hydrates without formation of hydrolyzed species can only be accomplished with difficulty. The actinide(iv) ions resemble Ce(iv) in forming fluorides and oxalates insoluble even in acid solution. The nitrates, sulfates, perchlorates, and sulfides are all water-soluble. The iv state actinide ions form insoluble iodates and arsenates even in rather strong acid solution. The... 

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