Potassium bisulphate

Method 2 (from potassium bromide and sulphuric acid). Potassium bromide (240 g.) is dissolved in water (400 ml.) in a litre flask, and the latter is cooled in ice or in a bath of cold water. Concentrated sulphuric acid (180 ml.) is then slowly added. Care must be taken that the temperature does not rise above 75° otherwise a little bromine may be formed. The solution is cooled to room temperature and the potassium bisulphate, which has separated, is removed by flltration through a hardened Alter paper in a Buchner funnel or through a sintered glass funnel. The flltrate is distilled from a litre distilling flask, and the fraction b.p. 124 127° is collected this contains traces of sulphate. Pure constant boiling point hydrobromic acid is obtained by redistillation from a little barium bromide. The yield is about 285 g. or 85 per cent, of the theoretical. 

Pyruvic acid is conveniently prepared by the distillation of tartaric acid with a dehydrating agent, such as potassium bisulphate ... 

A terpene yielding isofenchyl alcohol on hydration, which Wallach considers to be one of the fenchenes, was artificially prepared by converting nopinone into a hydroxy ester by means of bromoacetic ester and zinc-dust. The hydroxy ester is dehydrated by potassium bisulphate, and so yields an unsaturated ester, which on saponification yields an acid from which the terpene results by distillation. This fenchene has the following characters —... 

Komppa and Eoschier now propose a revision of the nomenclature of the fenchene terpenes, Wallach s D-fenchene being termed a-fenchene, D-Z-fenchene becoming Z-o-fenchene, and D-d-fenchene becoming d-a-fenchene. The fenchene obtained by Bertram and Helle s method, by dehydrating fenchyl alcohol with potassium bisulphate, is now termed y8-fenchene. This nomenclature is certainly preferable as it contains no suggestion that the two bodies are identical in chemical constitution, nor is there any particular evidence that D-Z-fenchene and L-Z-fenchene are not the same actual terpene, and equally so in the case of D-d-fenchene and L-d-fenchene. 

The latest contribution to the chemistry of this abstruse subject is contained in papers by Komppa and Eoschier, and by Eoschier. They have obtained a fenchene l>y treating methyl-/3-fenchocamphorol with potassium bisulphate, which is the inactive form of )8-fenchene, mixed with a small amount of a terpene they term y-fenchene. /3-fenchene (identical with D-(f-fenchene of Wallach), and y-fenchene have the following constitutions —... 

Thus it can be seen that evidence for the A-l mechanism, even if one accepted that this followed from a linear rate coefficient-acidity function correlation, was scant. On the other hand, there have been a very large number of carefully documented studies in which general acid catalysis has been observed leading to the A-Se2 mechanism for the reaction, or it has been shown that the conclusions from an acidity function dependence are not rigorous. One such study has already been described above, and Satchell478 also found that in the detritiation of [4,6-3H2]-l,2,3-trimethoxybenzene by potassium bisulphate, dichloro- and tri-fluoroacetic acids, plots of log kl versus —H0 were linear with a slope of ca. 1.0... 

Magnesium fluorosilicate Mercuric chloride Nickel chloride Nickel sulphate Potassium bisulphate Potassium bisulphite Potassium sulphite Silver nitrate... 

Potassium bisulphate and anhydrous boric or oxalic acid are also used (acrolein from glycerol, pyruvic acid from tartaric acid). Tschugaev s xanthate method belongs to this class of reactions also. 

Preparation of Potassium Persulphate. Assemble an apparatus shown in Fig. 74. Put 100 ml of a potassium bisulphate solution saturated at 0 °C (see Appendix 1, Table 1) into test tube 1. Immerse... 

Heavy Metals. — The solution of 1 gm. of potassium bisulphate in 20 cc. of water should not be affected by hydrogen sulphide water nor by ammonium sulphide solution when rendered slightly alkaline with ammonia water. 

Arsenic. — The mixture of 1 gm. of finely powdered potassium bisulphate with 3 cc. of stannous chloride solution should not acquire a dark color within one hour. 

Quantitative Determination. — Dissolve 1 gm. of potassium bisulphate in 50 cc. of water, and titrate with normal potassium hydroxide, using methyl orange as the indicator. 

With the remainder of the liquid, mixed with io c.c. of 10% potassium bisulphate solution and a few drops of acetic acid, two or three strands of well-defatted wool are heated on a water-bath for a long time. In presence of coal-tar dyes, the wool is coloured red, the colour persisting after washing with water. 

Colouring matters are also detected by treating the solution with a few drops of 10% potassium bisulphate solution and boiling the liquid for 10 minutes with a few threads of de-fatted wool immersed in it. If, after washing with water, the wool is coloured yellow, a coal-tar colour is indicated it may be identified by its behaviour towards reagents, as indicated for wines (q.v.). 

These mixtures are not completely soluble in 90% alcohol, except in presence of castor oil, which is, however, only slightly soluble in 70% alcohol. When, therefore, they are evaporated in a dish on a water-bath, they leave an abundant residue which has a high saponification number (180-200) and emits an irritating odour of acrolein when heated in a test-tube with potassium bisulphate. Certain ethereal oils (bergamot, lemon, aniseed and badiana oils) themselves leave a residue on evaporation, but such residue has not the characters of the fatty oils. The saponification number of the oil itself may raise suspicion as to the presence of fatty oil. 

After this operation, the liquid is evaporated to dryness and the residue taken up in a mixture of 2 vols. of absolute alcohol and 1 vol. of anhydrous ether. The solution is filtered, the solvent evaporated and the new residue heated with potassium bisulphate in presence of glycerine (from the saponification of the acetins) an odour of acrolein is emitted and the vapours impart a dark blue colour to a paper steeped in a fresh solution of sodium nitroprusside and piperidine. 

Glycerine,—The ink is evaporated to a syrup, which is taken up in 96% alcohol and the liquid filtered the alcoholic solution is evaporated and the residue tested for glycerine as follows A few drops are heated in a test-tube with a crystal of potassium bisulphate. In presence of glycerine, the irritating odour of acrolein is observed and a spot of sodium nitro-... 

The chemical examination of this product is usually limited to a few qualitative tests. A portion is treated with hot dilute hydrochloric acid, and the filtered liquid tested for calcium and sulphuric acid (chalk, gypsum). Another portion is either treated with hot concentrated sulphuric acid or fused with potassium bisulphate when cold the mass is treated with water and the solution tested for aluminium. 

The 2-naphthalenesulfonic acid, l,2,3,4-tetrahydro-2-methyl-l,4-dioxo-, sodium salt, trihydrate can be prepared by mixing the 2-methyl-l,4-naphthoquinone with the bisulphite salt in the presence of water. Ordinarily gentle warming of the aqueous mixture is preferred to facilitate solution. The mixture of 2-methyl-l,4-naphthoquinone (250 mg 1 molar equivalent) sodium bisulphite (149 mg 1 molar equivalent) distilled water (250 ml) or 2-methyl-1,4-naphthoquinone (250 mg 1 molar equivalent) potassium bisulphate (349 mg 2 molar equivalent) distilled water 250 ml may be used. These examples representing preferred ratios of ingredients are merely illustrative and are not to be interpreted as limiting. 

Prepared by fusing 1 part of titanium dioxide with 15 to 20 parts of potassium bisulphate and dissolving the mass in 500 cc. of cold 6 N sulphuric acid. 

SYNS ACID POTASSIUM SULFATE MONOPOTASSIUM SULFATE POTASSIUM ACID SULFATE POTASSIUM BISULPHATE POTASSIUM HYDROGEN SULFATE, solid (DOT) O SAL ENIXUM O SULFURIC ACID, MONOPOTASSIUM SALT... 

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