Alkali fixed

Insol in w, si sol in acet ac, sol in dil nitric ac fixed alkali hydroxides. Poisonoust Warren (Ref 1) evaluated Pb oxalate as a possible replacement for MF in primer compns, and concluded that it lacked the sensitivity necessary for an initiating agent. Sensitivity data obtained are given below ... 

Paraformaldehyde. (CH20)g, mw (30.03)n white, cryst powder mp 64, bp sublimes, range of polymerization n=8 to 100. Note Paraformaldehyde is not the same as sym-tri-oxane, which melts at 150—60°. Slowly sol in cold, more readily in hot w, with evolution of formaldehyde insol in ale eth sol in fixed alkali hydroxide solns. Obtained by concentrating formaldehyde soln. At ordinary temps, it gradually vaporizes, yielding formaldehyde gas... 

Organic solvent(s) Partition coefficients No data 1 g in 2,500 mL absolute alcohol 1 g in 75 mL absolute alcohol Soluble in alkali chlorides soluble in alkali (Massicot) insoluble in alcohol Soluble in fixed alkali hydroxides insoluble in alcohol... 

Bismuth dissolves in nitric acid and in aqua regia both solutions are precipitated by pure water in the form of a white powder. When the regulus of cobalt is dissolved in these menstrua, it cannot be precipitated from them except by the alkalies fixed alkali precipitates it in the form of a powder which, after being washed, remains dark and black whereas when one precipitates it with volatile alkali, especially if it has been dissolved by aqua regia, it acquires a very red color, which changes to blue, if one exposes it to the fire up to the point of redness (27). 

When A. S. Marggraf tried to prepare alum from alumina and vitriolic acid, he found that unless he added fixed alkali he obtained no crystals (19). In 1777 Lavoisier clearly stated that potash is an essential constituent of alum (18, 20). In analyzing a water containing aluminum sulfate, which the younger Cassini had sent him from Italy, Lavoisier added some potash When he evaporated the solution, he obtained crystals of alum and realized that this was a verification of the results of Marggraf and of Macquer. 

The celebrated Mr. Klaproth of Berlin, said Dr. Kennedy, has already shown that pot-ash enters into the composition of several stony substances, and by the experiments described in this paper, the other fixed alkali, soda, has also been proved to exist in mineral bodies, as it has been separated from nine different varieties. . . (25). 

Wall, M., Remarks on the origin of the vegetable fixed alkali, with some collateral observations on nitre, Memoirs Lit and Philos. Soc. (Manchester), 2, 67-79 (1789), 2nd ed. 

In commenting on this list he said, I have not included in this table the fixed alkalies, such as potash and soda, because these substances are evidently compound, although however the nature of the principles which enter into their composition is still unknown (30). The chemical nature... 

This alkali [continued Berzelius] has a greater capacity for saturating acids than the other fixed alkalies, and even surpasses magnesia. It is by this cir-... 

But [said he] it was still necessary to learn the base of the salt. Its solution could not be precipitated either by tartaric acid in excess or by platinum chloride. Consequently it could not be potassium. I mixed another portion of a solution of the same salt with a few drops of pure potash, but without its becoming cloudy. Therefore it contained no more magnesia hence it must be a salt with soda for a base. I calculated the quantity of soda which would be necessary to form it but it always resulted in an excess of about 5 parts in 100 of the mineral analyzed. Therefore, since it seemed probable to me that the different substances might not have been well washed, Or that the analysis might not have been made with sufficient precision in other respects, I repeated it twice more with all the care possible, but always with results very little different. I obtained. Silica. 78 45, 79.85, Alumina 17 20, 17.30 Sulfate 19.50, 17.75. At last, having studied this sulfate more closely, I soon found that it contained a definite fixed alkali, whose nature had not previously been known (21). 

Davy, H., The decomposition of the fixed alkalies and alkaline earths, Set. 

Davy, H, The Decomposition of the Fixed Alkalies and Alkaline Earths, ... 

Marggraf then collected clays from various places in Germany, Silesia, and Poland, and distilled them with sulfuric acid, but obtained no satisfactory crystals of alum. When he added fixed alkali in the proper amount, however, he obtained beautiful, large crystals of it (74). 

Lead Oxide, Yellow, or Litharge (Lead Monoxide, Lead Protoxide or Plumbous Oxide). PbO, mw 223.21, yellow to yellowish-red, heavy, odorless pdr or minute, cryst scales mp 888°, bp (vol at red heat) d 9.53g/cc insol in w, ale sol in acet ac, dil nitric acid, in warm solns of fixed alkali hydroxides. It may be prepd in the lab by heating Pb nitrate, carbonate or hydroxide commercially, it is made by heating Pb to a temp considerably above its mp and continually skimming off the litharge produced. It is used in some primer compns... 

Pierre-Joseph Macquers Elemens de chimie th orique, (1749) and Elemens de chimie practique (1751) became the first significant French successor to Nicholas Lemerys Cours de chymie, first published in 1675. Unlike earlier works it was an attempt to offer chemistry for its own sake, independent of medicine. It was intended for the absolute Novice in Chymistry to lead him from the most simple truths. .. to the most complex. Hence he begins with the elements, then moves on to saline substances (acids, alkalies, and their combinations) the volatile sulphureous spirit, sulphur, phosphorus, and the neutral salts, which have an earth or a fixed alkali for their bases. Then on to the metals, which are scarcely more compounded than the saline ... 

It is interesting to see that Lavoisier resolved this problem by analogy with well-established composition of other acids, a more demonstrable analogy than that of the fixed alkalies compound nature by analogy with ammonia. 

All salts are composed of two parts, of an acid and of a base. To assure myself that the acid of gypsum was that of vitriol, as I naturally presumed it to be, I placed in a small crucible some calcined pierre specu-laire along with some powdered charcoal. As soon as the material became red, the cover of the crucible became surrounded by a small blue flame. When the lid was removed, the surface of the material was seen to be covered with the same flame, and a slight odor of the volatile sul-furous acid could be detected. When the mixture so calcined had cooled, I added some acid to it. Immediately there was disengaged the odor of rotten eggs so that it was easy to identify the presence of liver of sulphur. I remade the same mixture of plaster and of charcoal in adding to it some fixed alkali, there resulted a true liver of sulphur. 

To determine the nature of the base, Lavoisier added to a solution of the gypsum some concentrated fixed alkali, drop by drop. Immediately the vitriolic acid left its base to unite with the fixed alkali and form with it vitriolated tartar [potassium sulfate]. The solution became turbid and a white precipitate formed, which when washed proved to be a very pure cal-... 

The term kali with the al prefix referred to the half-vitrified ashes, and hence the salts obtained from the ashes of plants were called- alkaline salts as well as nitrum. The term sal alchali for the ashes of sea-plants appears in the writings of the Latin Geber about the thirteenth century and the same term was also employed for the ashes of land-plants. It is known that the former furnishes a large proportion of sodium carbonate, the latter potassium carbonate. Later on, in order to distinguish these salts from ammonium carbonate, they were termed fixed alkalies, and ammonium carbonate was called volatile alkali. 

Near the end of the eighteenth century the difference between the two fixed alkalies—potassium and sodium carbonates—was known sodium carbonate barilla was largely made from the ashes of sea plants, and potash from the ashes of land plants. The Arabs also had brought some natural soda into Europe, via Spain. These sources were not sufficient to cope with the demand for alkali for the manufacture of soap, glass, etc. Potash was at that time the cheaper and dominant alkali. With the steadily increasing demands for alkali and the very limited sources of supply presented by the incineration of wood, many attempts were naturally made to substitute the base of common salt, because that with a suitable method of extraction nature has provided inexhaustible, abundant, and cheap... 

The fixed alkalies may be more easily separated from determine them conjointly by an indirect method. Hie ... 

When the fixed alkalies and magnesia are contained from all loss may be insured by employing a crucible ... 

Solutions of the fixed alkalies convert it into black oxide, and by ammonia it is changed into the double salt, 2 (Mg KHa), Hg, 01, which is also black. This amide compound is different from that which is formed when calomel and dry ammonia are brought in contact the last has, according to Kane, the formula 2 Hgs C1,H NH ... 

Most of them dissolve in solutions of the fixed alkalies, whether hot or cold, as also in ammonia, and form definite salts—re slnates—some of which are quite neutral, These resinates are soluble in water, and form a considerable portion of the cheaper kinds of soap, being themselves possessed of detergent qualities. RoBtnatcs of the alkaline earths, and of the heavy metallic oxides, may be prepared from those of the alkalies by double decomposition but they are insoluble, and generally strong acids liberate the resin from them unchanged. 

Salited lime (calcium chloride) is considered a useful test for fixed alkali, for the aerated lime (that is, carbonate) separates, but this experiment is ambiguous because if vitriolated magnesia (magnesium sulphate) be present, a double decomposition takes place and a gypsum is formed. ... 

Bergman explains why he prefers the term air acid or aerial acid to the then usual name—fixed air. In the first place, because this is only one of several kinds of air which occur fixed, and in the second place, because it is at the same time a true acid and a constant constituent of the atmosphere. Fixed air, he says, is a true acid, because it possesses a distinctly acid taste it reddens litmus ( turnsol ) it attacks caustic fixed alkalies, rendering them mild a smaller quantity of this acid than of the stronger acids saturates these alkalies and renders them crystallizable and less soluble it makes the volatile alkali (ammonia) more fixed, less odorous and penetrating and causes it to crystallize when it just saturates quicklime, it deprives it of its solubility and acrimony and causes... 

In 1773 it occurred to Priestley to apply the method he had used to obtain his marine acid air to see whether an alkaline air might be obtained from substances containing volatile alkali. He procured some volatile spirit of sal ammoniac (that is, ammonia water), placed it in a thin phial and heated it with a candle. A great quantity of vapor was discharged, which, collected over mercury, continued in the form of a transparent and permanent air, not at all condensed by cold. Sal volatile (that is, ammonium carbonate) and other salts obtained by the distillation of sal volatile with fixed alkalies, were tried but found to yield much fixed air also, so that he eventually used the mixture then customary for preparing the volatile spirit of sal ammoniac, viz., one part of sal ammoniac with three parts of slaked lime, which furnished him a large and easily controlled supply of pure alkaline air. ... 

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