Their salts

Concentrated sulphuric acid displaces more volatile acids from their salts, for example hydrogen chloride from chlorides (see above) and nitric acid from nitrates. The dilute acid is a good conductor of electricity. It behaves as a strong dibasic acid ... 

All the halic(V) acids are strong acids and their salts are not appreciably hydrolysed in aqueous solution. They are also powerful oxidising agents (see below). 

Originally, general methods of separation were based on small differences in the solubilities of their salts, for examples the nitrates, and a laborious series of fractional crystallisations had to be carried out to obtain the pure salts. In a few cases, individual lanthanides could be separated because they yielded oxidation states other than three. Thus the commonest lanthanide, cerium, exhibits oxidation states of h-3 and -t-4 hence oxidation of a mixture of lanthanide salts in alkaline solution with chlorine yields the soluble chlorates(I) of all the -1-3 lanthanides (which are not oxidised) but gives a precipitate of cerium(IV) hydroxide, Ce(OH)4, since this is too weak a base to form a chlorate(I). In some cases also, preferential reduction to the metal by sodium amalgam could be used to separate out individual lanthanides. 

Initially, the only means of obtaining elements higher than uranium was by a-particle bombardment of uranium in the cyclotron, and it was by this means that the first, exceedingly minute amounts of neptunium and plutonium were obtained. The separation of these elements from other products and from uranium was difficult methods were devised involving co-precipitation of the minute amounts of their salts on a larger amount of a precipitate with a similar crystal structure (the carrier ). The properties were studied, using quantities of the order of 10 g in volumes of... 

Note that the amino-acids, because of their salt-like nature, usually decompose on heating, and therefore seldom have sharp melting-points. Furthermore, all naturally occurring amino-acids are a-amino-acids, and consequently, with the exception of glycine, can exist in optically active forms. 

Heating the acids or their salts with soda lime eliminates the carboxyl group, volatile products being often detectable. 

By pyrolysis of dibasic acids or their salts to yield cyclic ketones. The slow distillation of adipic acid with about. 5 per cent, of baryta affords cyclo-pentanone in good yield ... 

Alkyl mercaptans are partly soluble in solutions of caustic alkalis, but their salts are hydrolysed in dilute aqueous solution back to the free mercaptans. Thiophenols are soluble in alkah hydroxide solutions. Upon treatment with sodium, hydrogen is evolved. 

Sulphonacetamides. Sulphonacetamides are derivatives of sul-phonamides (Section IV.33A), but since the latter are readily prepared from the sulphonic acids or their salts, sulphonacetamides may be employed for the characterisation of sulphonic acids for this reason they are included in this Section. 

The Lassaigne procedure for detecting nitrogen in organic compounds frequently gives unsatisfactory results with explosive compounds (diazonium salts, polynitro compounds and the like) and with certain volatile nitrogenous substances, such as bases, their acyl derivatives or their salts. These difficulties... 

It is also used as a reducing agent in the production of pure uranium and other metals from their salts. The hydroxide (milk of magnesia), chloride, sulfate (Epsom salts), and citrate are used in medicine. Dead-burned magnesite is employed for refractory purposes such as brick and liners in furnaces and converters. 

From the point of view of reactivity, there is little difference betvv een 2-amino-selenazoles and aryl- Or alkyl-2-aminoselenazoles, except that the A"-arvl derivatives are generallv less basic and that their salts are more easily hydrolyzed. 

Thiazole acetic acids and their hotnologs can also be prepared by cyclization procedures 4-thiazole alkanoic acids and their salts were prepared by treating a thioamide with a -y-chloro- or 7-bromoacetoacetic or their a-alkyl derivatives (4, 10, 16, 22, 273, 275, 281, 640, 647, 695). 

Similarly, 5-thiazole alkanoic acids and their salts are obtained from thioamides and /3-halo -y-keto acids (695). Thus thioarylamides condensed with 3-aroyl-3-bromopropionic acid (88) in isopropanolic solution in the presence of Na COs give first 4-hydroxy-2-aryl-A-2-thiazoline-5-acetic acid intermediates (89), which were dehydrated in toluene with catalytic amounts of p-toluene sulfonic acid to 2,4-diaryl-5-thiazole acetic acid (90) (Scheme 39) (657), with R = H or Me Ar = Ph, o-, m- or p-tolyl, o-, m-, or P-CIC6H4, 0-, m-, or p-MeOC(iH4, P-CF3C6H4, a-thienyl, a-naphthyl (657). 

Substitution of an ester of dithiocarbamic acid such as alkyl or benzyl ester (171), or their salts leads directly to 2-substituted mercaptothiazoles (172) (Scheme 87) (272, 461). Some of these compounds have an antifungal activity (561). 

Hydrogen peroxide Copper, chromium, iron, most metals or their salts, alcohols, acetone, organic materials, flammable liquids, combustible materials... 

Neunne. Neurine is trimethyl vinyl ammonium hydroxide, [463-88-7]. Tertiary amines and their salts vinylate readily at low... 

The basic flow sheet for the flotation-concentration of nonsulfide minerals is essentially the same as that for treating sulfides but the family of reagents used is different. The reagents utilized for nonsulfide mineral concentrations by flotation are usually fatty acids or their salts (RCOOH, RCOOM), sulfonates (RSO M), sulfates (RSO M), where M is usually Na or K, and R represents a linear, branched, or cycHc hydrocarbon chain and amines [R2N(R)3]A where R and R are hydrocarbon chains and A is an anion such as Cl or Br . Collectors for most nonsulfides can be selected on the basis of their isoelectric points. Thus at pH > pH p cationic surfactants are suitable collectors whereas at lower pH values anion-type collectors are selected as illustrated in Figure 10 (28). Figure 13 shows an iron ore flotation flow sheet as a representative of high volume oxide flotation practice. 

Methylamines are formed by heating formaldehyde with primary or secondary amines or their salts under acid conditions (61) ... 

Natural gas and its combustion properties appear to have been known since early times (2). Some early temples of worship were located in areas where gas was seeping from the ground or from springs, and it is reported that Julius Caesar saw a phenomenon called the "burning spring" near Grenoble, France. Gas wells were drilled in Japan as early as 615 AD and in 900 AD the Chinese employed bamboo tubes to transport natural gas to their salt works, where the heat was used to evaporate water from salt brine. The existence of natural gas in the United States was reported by early setders who observed gas seeps and columns of fire in the Ohio Valley and the Appalachian area in 1775 (3). 

Eithei oxidation state of a transition metal (Fe, Mn, V, Cu, Co, etc) can activate decomposition of the hydiopeioxide. Thus a small amount of tiansition-metal ion can decompose a laige amount of hydiopeioxide. Trace transition-metal contamination of hydroperoxides is known to cause violent decompositions. Because of this fact, transition-metal promoters should never be premixed with the hydroperoxide. Trace contamination of hydroperoxides (and ketone peroxides) with transition metals or their salts must be avoided. 

MIBK is a highly effective separating agent for metals from solutions of their salts and is used in the mining industries to extract plutonium from uranium, niobium from tantalum, and zirconium from hafnium (112,113). MIBK is also used in the production of specialty surfactants for inks (qv), paints, and pesticide formulations, examples of which are 2,4,7,9-tetramethyl-5-decyn-4,7-diol and its ethoxylated adduct. Other appHcations include as a solvent for adhesives and wax/oil separation (114), in leather (qv) finishing, textile coating, and as a denaturant for ethanol formulations. 

Collectors ndFrothers. Collectors play a critical role ia flotation (41). These are heteropolar organic molecules characterized by a polar functional group that has a high affinity for the desired mineral, and a hydrocarbon group, usually a simple 2—18 carbon atom hydrocarbon chain, that imparts hydrophobicity to the minerals surface after the molecule has adsorbed. Most collectors are weak acids or bases or their salts, and are either ionic or neutral. The mode of iateraction between the functional group and the mineral surface may iavolve a chemical reaction, for example, chemisorption, or a physical iateraction such as electrostatic attraction. 

Peroxophosphoric Acids and Their Salts. In its usual impure form (H PO is the main contaminant), peroxomonophosphoric acid [13598-52-2] (5), is a viscous, coloress Hquid. The three ionization constants for peroxomonophosphoric acid are pifj = 1.1, P-A2 = 5.5, and pK (peroxide proton) = 12.8 (44). Oxidations comparable to those of peroxomonosulfuric acid, H2SO, occur in acid solutions of ca pH 2, but at higher pH values, H PO becomes less reactive as an oxidant and more unstable with respect to decomposition (44). The stmcture of H PO is probably similar to that of... 

Peroxosulfiiric Acids and Their Salts. Two kiads of peroxosulfiiric acid are known peroxomonosulfuric and peroxodisulfuric acids. Neither is available commercially ia the pure state. The name Caro s acid is commonly used as a synonym for peroxomonosulfuric acid, but is better reserved for the equiUbrium mixture with sulfuric acid. 

Organoperoxysulfonic acids and their salts have been prepared by the reaction of arenesulfonyl chlorides with calcium, silver, or sodium peroxide treatment of metal salts of organosulfonic acids with hydrogen peroxide hydrolysis of di(organosulfonyl) peroxides, RS(0)2—OO—S(02)R, with hydrogen peroxide and sulfoxidation of saturated, non aromatic hydrocarbons, eg, cyclohexane (44,181). 

Phenol s chemical properties are characterized by the influences of the hydroxyl group and the aromatic ring upon each other. Although the stmcture of phenol is similar to cyclohexanol, phenol is a much stronger acid. Its piC in aqueous solution at 25°C is 9.89 x 10 ° (8). This characteristic allows aqueous hydroxides to convert phenol into their salts. The salts, especially those of sodium and potassium, are converted back into phenol by aqueous mineral acids or carboxyhc acids. 

Phosphonic acid and hydrogen phosphonates are used as strong but slow-acting reducing agents. They cause precipitation of heavy metals from solutions of their salts and reduce sulfur dioxide to sulfur, and iodine to iodide in neutral or alkaline solution. 

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