Perchloric acid monohydrate

It is certain that the proton does not exist by itself in water. The simplest formula found in some crystalline salts is H30+. For example, crystals of perchloric acid monohydrate contain pyramidal hydronium (also called hydroxonium) ions ... 

Earlier Hantzsch et al. [21] thought the precipitate in question was nitracidium and hydronitracidium perchlorates (p. 13, Vol. I). However Ingold et al. [22] showed that Hantzsch s product is a mixture of perchloric acid monohydrate and nitryl perchlorate. 

Both are ionic substances with lattice sites occupied by cations and anions. In perchloric acid monohydrate, the cation is H30+ and there are no water molecules of hydration. The cations in the two crystals, H30+ and NH ", should occupy nearly equal amounts of space because they are isoelectronic (having the same number of electrons). 

Concentrated sulphuric acid no visible action with the solid salt in cold, on strong heating white fumes of perchloric acid monohydrate are produced ... 

On the other hand, although for many years acetic acid has been the most popular solvent for titration of bases, acetonitrile - which is a considerably weaker base and much weaker acid than water - shows a greater pH jump in the titration curves of bases. Acetonitrile solvation of anions is less than that of cations and, from an analytical viewpoint, conjugation is negligible for bases. This fact makes acetonitrile very suitable for the determination of very weak bases and mixtures of bases. In this medium many workers have used a solution of perchloric acid in anhydrous acetic acid as a titrant. However, for the differentiating titration of two or more bases of different strengths, it is necessary to avoid the leveling effect of acetic acid, whose presence decreases the potential break in acetonitrile, especially in the basic side. A solution of perchloric acid monohydrate in nitromethane is stable and very suitable for titrations in acetonitrile. 

The first member of the series, CF SO H, has been extensively studied. Trifluoromethanesulfonic acid [1493-13-6] is a stable, hydroscopic Hquid which fumes in air. Addition of an equimolar amount of water to the acid results in a stable, distillable monohydrate, mp 34°C, bp 96°C at 0.13 kPa (1 mm Hg) (18). Measurement of conductivity of strong acids in acetic acid has shown the acid to be one of the strongest protic acids known, similar to fluorosulfonic and perchloric acid (19). 

Bismuth Triperchlorate Pentahydrate. Bismuth(III) perchlorate pentahydrate [66172-92-7], Bi(C10 2 5H20, is prepared by dissolving Bi202 in 70% HCIO4. Anhydrous bismuth triperchlorate [14059-45-1], Bi(C10 2> maybe prepared by heating bismuthyl perchlorate monohydrate [66172-93-8], BiOClO H2O, between 80 and 100°C. Attempts to dissolve bismuth metal in concentrated perchloric acid have resulted in explosions. Treatment of bismuth or with dilute solutions of perchloric acid yields hydrates of bismuthyl perchlorate. 

The monohydrate is light-sensitive and explodes at 96-97°C if heated at 2°/min [1]. It effervesces vigorously on dissolution in perchloric acid [2],... 

Ethylbenzene, Thallium triacetate Ucmura, S. et al., Bull. Chem. Soc., Japan., 1971, 44, 2571 Application of a published method of thallation to ethylbenzene caused a violent explosion. A reaction mixture of thallium triacetate, acetic acid, perchloric acid and ethylbenzene was stirred at 65°C for 5 h, then filtered from thallous salts. Vacuum evaporation of the filtrate at 60°C gave a pasty residue which exploded. This preparation of ethylphenylthallic acetate perchlorate monohydrate had been done twice previously and uneventfully, as had been analogous preparations involving thallation of benzene, toluene, three isomeric xylenes and anisole in a total of 150 runs, where excessive evaporation had been avoided. 

Acids that are used in addition to trifluoroacetic acid include trifluoroacetic acid with added sulfuric acid203 or boron trifluoride etherate,210,211 perfluorobu-tyric acid,212 hydrogen chloride/aluminum chloride,136,146,213 perchloric acid in chloroform,214 p-loluenesull onic acid alone134 or with aluminum bromide or aluminum chloride,192 concentrated sulfuric acid in two-phase systems with dichloromethane, alcohol, or ether solvents,209,215 trifluoromethanesulfonic acid,216 chlorodifluoroacetic acid,134 and the monohydrate of boron trifluoride... 

Darwish and Tomilson (166) first reported that deprotonation of optically active methylethylphenacylsulfonium perchlorate (2) by means of sodium methoxide affords the optically active ethylmethyl-sulfonium phenacylide 127. The ylide 127 has also been resolved into optically active forms via diastereomeric salts with chiral diben-zoyltartaric acid monohydrate (167). 

F. von Stadion s preparation (1816) was really an aq. soln. containing about 70 per cent, of HCIO4 G. S. Serullas preparation (1831) was the crystalline monohydrate, HC104.H20, which was mistaken for the pure acid until H. E. Roscoe11 demonstrated that it contained water, and by fractional distillation obtained from it a small quantity of what he called pure perchloric acid. H. E. Roscoe s directions are ... 

Anhydrous perchloric acid does not freeze when cooled by solid carbon dioxide, but its freezing point is —112°. The f.p. curve of mixtures of water and perchloric acid was investigated by H. J. van Wijk, and he found indications of the existence of six hydrates of perchloric acid, containing respectively 1, 2, 2, 3, and 3 H20— the hydrate with 3H20 exists in two different forms. The m.p. curve is shown in Fig. 28. The eutectic between the monohydrate HC104.H20 and the anhydrous acid lies virtually at the m.p. of the latter, —112° in consequence the m.p. curve... 

The formation and decomposition of Crv in aqueous and non-aqueous media during the oxidation of organic substrates such as oxalic acid and ethylene glycol by potassium dichromate has been recognized for some time. No study resulted in the isolation of a stable, well-characterized chromium(V) complex until 1978 when potassium bis(2-hydroxy-2-methylbutyrato)oxochromate(V) monohydrate was prepared from chromium trioxide and the tertiary a-hydroxy acid in dilute perchloric acid according to equation (91). The Crv, which is... 

The hydrates of perchloric acid exist in at least six crystalline forms. The monohydrate is composed of H30+ and CIO4 connected by hydrogen bonds. All perhalate ions XO4 are tetrahedral, with 7h symmetry, as shown below ... 

Silver perchlorate Perchloric acid, silverfl +) salt, monohydrate (8,9) (14242-05-8)... 

Lithium perchlorate, Li CIO 4.—The perchlorate is prepared by neutralizing perchloric acid with lithium carbonate, evaporating to dryness, extracting with alcohol, and concentrating the alcoholic solution. From aqueous solution the trihydrate, LiC104,3H20, crystallizes. It melts at 95° C., passes into the monohydrate at 98° to 100° C., and into the anhydrous salt at 130° to 150° C. The anhydrous salt melts at 236° C., and is converted with evolution of oxygen into the chlorate and chloride above 380° C.2 Between 4103 C. and 430° C. the decomposition is slow, but it becomes rapid at 450° C.3... 

Perchloric acid, HC104 H20, is a colorless liquid made by distilling, under reduced pressure, a solution of a perchlorate to which sulfuric acid has been added. The perchloric acid distills as the monohydrate, and on cooling it forms crystals of the monohydrate. These crystals are isomorphous with ammonium perchlorate, NH4CIO4, and the substance is presumably hydronium perchlorate, (H30) + (C104) . ... 

The monohydrate of perchloric acid was prepared by G. S. Serullas 2 in 1831, and mistaken for anhydrous perchloric acid until H. E. Roscoe prepared the latter in 1862. A. Michael and W, T. Conn isolated the anhydride of perchloric acid— chlorine heptoxide, CI2O7— in 1900. 

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