Thorium perchlorate

Thorium metal, 24 759-761 in alloys, 24 760-761 preparation of, 24 759-760 properties of, 24 760-761 reactions of, 24 761 Thorium nitrate, 24 757, 766 Thorium oxalates, 24 768-769 Thorium oxide, 21 491 Thorium oxides, 24 757, 761-762 Thorium oxyhalides, 24 762 Thorium perchlorate, 24 764 Thorium phosphates, 24 765-766 Thorium pnictides, 24 761 Thorium sulfate, 24 764 Thorium-uranium fuel cycle, 24 758-759 Thorocene, 24 772 Thorotrast, 24 775-776 3A zeolite. See Zeolite 3A Three-boiling beet sugar crystallization scheme, 23 463-465 Three-color photography, 19 233-234 3D models, advantages of, 19 520-521 3D physical design software, 19 519-521 3D QSAR models, 10 333. See also QSAR analysis... 

P. T. Cleve obtained an amorphous mass—presumably of thorium perchlorate—by treating thorium sulphate in a similar way. F. P. Yenable and I. W. Smithey prepared zirconyl perchlorate by dissolving zirconium hydroxide in 30 per cent, perchloric acid with 60 per cent, acid, the hydroxide dissolves... 

For thorium there are only estimates of the corresponding potential. An early estimate, of -2.4 V, was based on a relation between this quantity and the frequency of the first electron transfer absorption band in the UV spectrum of an aqueous thorium perchlorate solution (9). However, the spectral measurements did not quite reach the absorption maximum, and the necessary extrapolation introduced some uncertainty. Another value, -3.6 V, was based on the RESPET treatment of J0rgensen (10,11). The adjustable parameters in the RESPET equation were fixed using experimental values for other actinide elements (12). This method yields a value of -0.69 V for U(IV)/(III). Another rather simple method correlates this potential with the number of 5/"electrons for the element and gives -3.41 V for thorium and -0.54 V for uranium (13). A more sophisticated estimate (14), using a method proposed by Nugent et al. (12) (described later), gave -3.8 V for thorium. 

Perchlorates and iodates. Thorium perchlorate forms upon dissolution of thorium hydroxide in perchloric acid and crystallizes as Th(C104)4 4H20. The precipitation of tetravalent actinides as iodates has long been used to separate these elements from lanthanides at low pH. One of the earliest forms that Pu was isolated in was that of Pu(I03)4. The structure and most properties of Pu(103)4 are currently unknown, but a remarkable feature is that it is insoluble in 6M HNO3. 

Gayer and Leider [1954GAY/LE1] studied the solubihty of Th(lV) hydroxide in HCIO4 and NaOH solutions at 25°C. The solid, designated as thorium hydroxide ThO(OH)2(s), was precipitated from thorium perchlorate solution by adding an excess of NaOH, washed with water and used for solubility experiments in following media ... 

Thorium perchlorate crystallizes as colorless Th(C104)4 4H20. 

The most popular device for fluoride analysis is the ion-selective electrode (see Electro analytical techniques). Analysis usiag the electrode is rapid and this is especially useful for dilute solutions and water analysis. Because the electrode responds only to free fluoride ion, care must be taken to convert complexed fluoride ions to free fluoride to obtain the total fluoride value (8). The fluoride electrode also can be used as an end poiat detector ia titration of fluoride usiag lanthanum nitrate [10099-59-9]. Often volumetric analysis by titration with thorium nitrate [13823-29-5] or lanthanum nitrate is the method of choice. The fluoride is preferably steam distilled from perchloric or sulfuric acid to prevent iaterference (9,10). Fusion with a sodium carbonate—sodium hydroxide mixture or sodium maybe required if the samples are covalent or iasoluble. 

For many years fluorine has been deterrnined by the Willard-Winters method in which finely ground ore, after removal of organic matter, is distilled with 72% perchloric acid in glass apparatus. The distillate, a dilute solution of fluorosiUcic acid, is made alkaline to release fluoride ion, adjusted with monochloroacetic acid at pH 3.4, and titrated with thorium nitrate, using sodium a1i2arine sulfonate as indicator. 

Oxo Ion Salts. Salts of 0x0 ions, eg, nitrate, sulfate, perchlorate, hydroxide, iodate, phosphate, and oxalate, are readily obtained from aqueous solution. Thorium nitrate is readily formed by dissolution of thorium hydroxide in nitric acid from which, depending on the pH of solution, crystalline Th(N02)4 5H20 [33088-17 ] or Th(N02)4 4H20 [33088-16-3] can be obtained (23). Thorium nitrate is very soluble in water and in a host of oxygen-containing organic solvents, including alcohols, ethers, esters, and ketones. Hydrated thorium sulfate, Th(S0 2 H20, where n = 9, 8, 6, or 4, is... 

Z 1 Niobium 1 Nitrate 1 Osmium 73 a. I Perchlorate Phenols u a o Platinum o 0. 1 5 u 1 Rhodium 1 Rubidium Ruthenium Scandium 1 Selenium Silver I Sodium 1 Strontium 1 Sulphate Sulphides, organic Sulphur dioxide 1 Tantalum 1 Tellurium 1 Thallium Thorium e H 1 Titanium a u ab a 1- I Uranium 1 Vanadium 1 Yttrium 1 Zinc Zirconium... 

Douglas investigated heats of formation of dimethyl sulphoxide (and also of the sulphone) and proposed in a footnote that it could be determined by 5-min reaction with potassium permanganate/sulphuric acid, then adding excess iron(II) sulphate and finally titrating with permanganate. The same principle was used by Krishnan and Patel to determine dimethyl sulphoxide in various complexes (with perchlorates of titanyl, zirconyl and thorium), and by Krull and Friedmann to determine the same compound but using only dilute sulphuric acid and 5-min reaction. 

Thermal analysis has proved useful in determining the number of sulfoxide moieties which are lattice-held in a given complex. For example, the thorium and zirconyl perchlorate complexes of Me2SO undergo thermal degradation (Eqs. (2) and (3)]. 

Write the formulas for the following ionic compounds (a) lithium hydride (b) calcium bromate (c)chromium(II) oxide id) thorium(IV) perchlorate (e) nickel phosphate if) zinc sulfate. 

The four-valent Th4+ ion, which also forms primarily ionic bonds, has a hydration number of eight in aqueous perchlorate solutions (126), which is the same as that of erbium(III), although the Th—H20 bonds are slightly longer, 2.49 A, than for erbium(III), 2.35 A. Diffraction data for an aqueous thorium(IV) chloride solution, with a composition... 

Bidentate coordination of one or two perchlorates has been proposed in a thorium(IV) complex of composition Th(Ph3P0)4(C104)4 (20). 

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