Alkali solubility

Forms water-soluble alkali and alkaline earth metal salts. Heating with KCN gives benzonitrile and phenol is formed by fusion with NaOH or KOH. Further sulphonation at 250°C gives benzene-1,3-disulphonic acid. 

The redox properties have already been considered. A number of reactions of soluble (alkali metal) sulphites are noteworthy ... 

Steaming-out the steam distillation apparatus. After the cleaned steam -distillation apparatus (Fig. 88) has been assembled, it is essential to pass steam through it for some time to remove readily soluble alkali. All the taps on the apparatus are opened and the water in the steam generator boiled vigorously. The steam will gradually pass into the apparatus. After a few minutes, the tap of the tap-funnel C may be closed and soon afterwards the tap Ti of the steam-trap finally the tap Tj of the funnel G may be closed, Steaming-out should then be continued for not less than one hour, the receiver J not being in place. 

Bemoyl chloride may replace acetyl chloride as a class reagent it possesses the advantage that it is only very slowly decomposed by cold water and consequently may be employed for detecting alcohols even in aqueous solution. The reaction is usually carried out in aqueous solution containing sufficient caustic alkali to decompose any excess of benzoyl chloride into the water-soluble alkali benzoate (Schotten - Baumann reaction compare Section IV,52). The benzoyl esters formed are insoluble in water ... 

Exhaustive oxidation of sulphones to sulphate using a mixture of potassium chlorate, sodium peroxide and sugar in a bomb has also been recommended220. This procedure is known as the Parr method and produces a mixture of soluble alkali sulphates. 

Polycarboxylated polyalkoxylates and their sulfate derivatives may be prepared by reacting an ethoxylated or propoxylated alcohol with a water-soluble, alkali or earth alkali metal salt of an unsaturated carboxylic acid [339]. The reaction occurs in aqueous solution in the presence of a free radical initiator and gives products of enhanced yield and reduced impurity levels, compared with the essentially anhydrous reactions with free carboxylic acids, which have been used otherwise. The method provides products that give solutions that are clear on neutralization, remain clear and homogeneous on dilution, and are useful as cleaning agents in drilling and other oil field operations. 

The alkali metal cyanides are very soluble in water. As a result, they readily dissociate into their respective anions and cations when released into water. Depending on the pH of the water, the resulting cyanide ion may then form hydrogen cyanide or react with various metals in natural water. The proportion of hydrogen cyanide formed from soluble cyanides increases as the water pH decreases. At pH <7, >99% of the cyanide ions in water is converted to hydrogen cyanide (Towill et al. 1978). As the pH increases, cyanide ions in the water may form complex metallocyanides in the presence of excess cyanides however, if metals are prevalent, simple metal cyanides are formed. Unlike water-soluble alkali metal cyanides, insoluble metal cyanides such as are not expected to degrade to hydrogen cyanide (Callahan et al. 1979). 

Thiatriazole-5-thiol and its salts are readily obtained from the water-soluble alkali or alkaline earth azides with CS2 at 40 °C <64AHC(3)263>. However, these salts should be handled with extreme care as violent explosions have been reported when the alkali salts are spread on a porous plate or rubbed with a spatula. The slightly soluble heavy-metal salts are very sensitive to shock even under water. An improved method for the preparation and storage of sodium thiatriazole-5-thiolate has been reported. The free acid is obtained by addition of concentrated hydrochloric acid to a chilled solution of the sodium salt but can also be prepared from hydrazoic acid and carbon disulfide (Scheme 38). 

Water-soluble alkalis in Portland cement or fly ash can have a harmful effect on the characteristics of the air-void stmcture (AVS), particularly the stability of the spacing factor. Because of the more restrictive environmental... 

Although previous investigations [132, 134, 135] have shown that increased soluble alkalis could have an important influence on the AVS, more recent work [136, 137], however, indicates that soluble alkalis per se do not influence the production of the AVS. It is only when the sulfate level (inherent or by extraneous addition) is high that the AVS production is difficult. An increase in the soluble-alkali content of cement has been found to improve significantly the stability of AVS, particularly in concrete mixtures to which a superplasticizer (SP) is added [138]. 

Tellurates. The water-soluble alkali metal and alkaline-earth tellurates are prepared by chlorinating alkaline solutions of the tellurites or by heating solid tellurites with KN03, KQ03, or Pb02 to form, for example, potassium tellurate [7790-58-1], Iv-TeO,. The insoluble tellurates are made by... 

Dimercapto-l,2,4-thiadiazole is soluble in water and ether. Its water-soluble alkali salts are difficult to crystallize, but the barium salt, which forms several hydrates, may be purified by crystallization. 146 Heavy metal salts are often colored144,203 and are soluble in potassium perthiocyanate solution.144... 

The alkali niobates are most conveniently prepared by the action of caustic alkalis on niobic acid or on solutions of niobium oxytri-fluoride. Other compounds of niobic acid and bases are generally prepared by fusing niobic add with the oxide, hydroxide, carbonate, or other salt of the metal. Occasionally double decomposition of a soluble alkali niobate and a soluble salt of the metal has been employed. Larsson s method1 consists in predpitating a solution of potassium niobate with a salt of a metal the dried predpitate is fused for thirty-six hours at a high temperature with boric acid, and the melt is boiled with water to which hydrochloric acid has been added. The residue consists of crystals of the insoluble niobate of the metal, usually the metaniobate. 

Tantalum pentoxide is insoluble in solutions of caustic alkalis and alkali carbonates, but on being fused with these substances reacts to produce the alkali tantalates. Tantalates of the metals are obtained by double decomposition, using a soluble alkali tantalate and a soluble salt of the metal. Tantalates of the alkaline earths have also been obtained by fusing tantalum pentoxide with the chloride of the alkaline earth. 

The soluble alkali tantalates undergo ready hydrolysis when their aqueous solutions are boiled, precipitation of a more add salt takes place and some alkali base passes into solution. Separation of the base in this manner is naturally favoured by the presence of acids, and even so weak an acid as carbon dioxide or hydrogen sulphide pretipitates tantalic add or an acid salt with the stronger adds (sulphurous acid, sulphuric add, hydrochloric acid, nitric add, etc., but not with hydrofluoric add) predpitation of tantalic add takes place readily, but excess of the strong mineral add redissolves the predpitate. Potassium chloride... 

Since the discovery in 1964 that the antibiotic valinomydn exhibited alkali cation specificity in rat liver mitochondria, a new area of research has developed, based not only on biological systems but also on model systems such as crown ethers.484 The ability of neutral compounds to form lipid-soluble alkali and alkaline earth complexes was observed in 1951. The structure of the corresponding ligand, the anion of the antibiotic nigericin (78), was characterized as its silver salt in 1968.488 486 Silver was used as a heavy atom crystaUographically, since the Ag+ cation had a radius between that of Na+ and K+, which were the two alkali cations with which nigericin was most active. 

Electrochemical Process. Several patents claim that ethylene oxide is produced in good yields in addition to faradic quantities of substantially pure hydrogen when water and ethylene react in an electrochemical cell to form ethylene oxide and hydrogen (206—208). The only raw materials that are utilized in the ethylene oxide formation are ethylene, water, and electrical eneigy. The electrolyte is regenerated in situ, ie, within the electrolytic cell. The addition of oxygen to the ethylene is activated by a catalyst such as elemental silver or its compounds at the anode or its vicinity (206). The common electrolytes used are water-soluble alkali metal phosphates, borates, sulfates, or chromates at ca 22—25°C (207). The process can be either batch or continuous (see Electrochemical processing). 

When hydrogen sulfide reacts, with mercuric chloride in neutral or acid solution, or when mercury and sulfur are ground together, black mercuric sulfide is formed. Under certain conditions, this material can be converted into the red modification by the continued action of soluble alkali sulfides. The reaction of mercuric chloride and sodium thiosulfate gives the red form if the ratio of the concentrations is higher than 1 4d The red sulfide is also produced when the substance Hg(SH)NCS is boiled with concentrated ammonium thiocyanate solution or when hydrogen sulfide is conducted into a warm mercuric salt solution in the presence of acetic acid and an excess of ammonium thiocyanate, or thiourea.2,3... 

INFLUENCE OF SOLUBLE ALKALIS ON THE STABILITY OF THE AIR-VOID STRUCTURE... 

Sol-gel silica synthesis is based on the controlled condensation of Si(OH)4 entities. These may be formed by hydrolysis of soluble alkali metal silicates or of alkoxysilanes. The commonly used compounds are sodium silicates and tetraethoxysilane (TEOS). 

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