Sulphur and water

Sulphur and water tolerance of perovskite-based catalysts for stationary sources... 

For a given diagram the activity of the sulphur solution species can be set to any desired value. The activity of elemental sulphur and water are both unity. The logarithms of the activities of the hydrogen ion and the electron are for convenience assigned the symbols X and Y respectively. Thus X = -pH and Y = -pE. For the particular case of reaction 1,3 the following equation is obtained for AG/R T where R = R In 10... 

Hydrogen from H S Throughout the discussion of refinery desul-phurisation the common sulphur containing end product has been H2S. After extraction from the main feedstock stream by an appropriate physical or chemical absorption method the H2S concentration is normally high enough to be fed to a Claus reactor where the H2S is converted to elemental sulphur and water. 

Traces of pentathionic acid are also stated to be found in the condensed liquid from the interaction of steam and sulphur vapour at a red heat,2 and in a mixture of sulphur and water after exposure to atmospheric oxidation.3 In the former ease the pentathionic acid probably results after the high temperature reaction by the interaction of sulphur dioxide and hydrogen sulphide in the condensate. 

The conventional Claus reaction involves the partial oxidation of hydrogen sulphide to sulphur and water. In practice the reaction is generally viewed as a two step sequence involving a highly exothermic oxidation step followed by a less exothermic redox reaction but the overall reaction can be expressed as... 

The base peak (76) in the mass spectrum of chaetocin represents the favoured loss of sulphur and water and splitting in half to give the stabilized, conjugated ion. The structure of chaetocin, which was shown by labelling experiments to... 

The Muslim alchemists adhered essentially to the Aristotelian philosophy, although they modified it in certain ways. In particular, the sulphur-mercury theory appears basically as a derivative of the theory of the Four Elements. The apposition of the two opposed, or contrary, elements, fire and w ater, now assumed a new guise. Fire became Sulphur, and Water became Mercury, These names must not be identified with the material substances, sulphur (brimstone) and mercury (quicksilver). They denoted abstract principles, composed of hot and dry (sulphur) and cold and moist (mercury) natures. In alchemical writings they were often called sophic (or philosopher s) sulphur and sophic mercury, or our ... 

In this publication Frankland also reported the use of diethyl ether as a diluent in reactions of ethylzinc with iodine, bromine, sulphur and water without it these reactions were reported to proceed too violently. 

Claus process A two-stage process used for the removal of sulphur from natural gas or crude oil. In the first, hydrogen sulphide is partially oxidized using air to form sulphur dioxide. In the second, the sulphur dioxide is reacted with the hydrogen sulphide in the presence of a catalyst at 300°C to form elemental sulphur and water vapour ... 

Tellurium trioxide, TeOa, is an orange yellow powder made by thermal decomposition of telluric(VI) acid Te(OH)g. It is a strong oxidising agent which will, like H2Se04, oxidise hydrogen chloride to chlorine. It dissolves in hot water to give telluric(VI) acid. This is a weak acid and quite different from sulphuric and selenic acids. Two series of salts are known. 

Sulphur and selenium form the chlorides disulphur dichloride S2CI2 and diselenium dichloride Se2Cl2. They are made by the direct combination of the elements. Both are covalent, yellow liquids which are readily hydrolysed by water ... 

Sulphur oxide dichloride is a colourless liquid which fumes in moist air. It is hydrolysed by water to give a mixture of sulphurous and hydrochloric acids ... 

CH3COOH + HOC2H5 - CH3GOOC2H3 + H2O If, however, concentrated sulphuric acid is present, the water is absorbed, the back reaction prevented, and a high yield of ethyl acetate is obtained. In practice the reaction is not so simple. It was formerly supposed that, since the sulphuric acid is usually added to the alcohol, ethyl hydrogen sulphate and water are formed, the latter being absorbed by the excess of sulphuric acid, A mixture of ethanol and acetic acid is then added to the ethyl hydrogen sulphate,... 

Add cautiously 15 ml. of concentrated sulphuric acid to 50 ml. of water in a 100 ml. distilling-flask, and then add 10 g. of pinacol hydrate. Distil the solution slowly. When about 40 ml. of distillate (consisting of pinacolone and water) have been collected, and no more pinacolone comes over, extract the distillate with ether. Dry the extract over sodium sulphate. Distil the dry filtered extract carefully, with the normal precautions for ether distillation (p. 164). When the ether has been removed, continue the distillation slowly, rejecting any fraction coming over below 100 . Collect the pinacolone, b.p. 106 , as a colourless liquid having a peppermint odour. Yield, 4 5-5 o g. A small quantity of higher-boiling material remains in the flask. 

Dissolve 5 g. (5 ml.) of aniline in 50 ml. of warm dilute sulphuric acid in a conical flask and add 50 ml. of water. Place a thermometer in the solution, immerse the flask in a mixture of ice and water, and cool until the temperature of the stirred solution falls to 5°. Dissolve 4-5 g. of powdered sodium nitrite in 20 ml. of water, and add this solution in small quantities (about 2-3 ml. at a time) to the cold aniline sulphate solution. Keep tne latter well shaken and maintain the temperature at about 5° (see p. 183). When all the sodium nitrite solution has been added, transfer about 5 ml. of the cold solution to a test-tube for each of the following reactions. The remainder of the diazonium hydrogen sulphate solution must be kept in ice-water until required, and then when all the reactions have been carried out, the solution should be poured down the sink. 

The method of hydrolysis depends on the nature of the product. It is usually sufficient to add dilute sulphuric acid to the ethereal solution and to shake thoroughly, when the magnesium enters the aqueous solution, whilst the organic compound remains in the ether. Alternatively, however, the ethereal solution may be poured on to ice and water, and then treated with dilute sulphuric acid. Should the product be affected by this acid, the hydrolysis can be carried out with an aqueous solution of ammonium chloride. In the following examples the hydrolysis is usually shown as a simple double decomposition... 

Principle. A known weight of the substance is heated with fuming nftric acid in a sealed tube, the organic material being oxidised to carbon dioxide and water, and the sulphur to sulphuric acid. The latter is subsequently washed out of the tube, precipitated as barium sulphate, and estimated as such... 

Dibromobutane from 1 4 butanediol). In a 500 ml. threenecked flask fltted with a stirrer, reflux condenser and dropping funnel, place 154 g. (105 ml.) of 48 per cent, hydrobromic acid. Cool the flask in an ice bath. Add slowly, with stirring, 130 g. (71 ml.) of concentrated sulphuric acid. To the resulting ice-cold solution add 30 g. of redistilled 1 4-butanediol dropwise. Leave the reaction mixture to stand for 24 hours heat for 3 hours on a steam bath. The reaction mixture separates into two layers. Separate the lower layer, wash it successively with water, 10 per cent, sodium carbonate solution and water, and then dry with anhydrous magnesium sulphate. Distil and collect the 1 4-dibromo-butane at 83-84°/12 mm. The yield is 55 g. 

Immediately the reaction is complete, introduce through the condenser 250 ml. of 50 per cent, sulphuric acid (by weight) whilst cooling the mixture in ice and water and stirring vigorously. Transfer the mixture to a separatory funnel, remove the ether layer, and extract the aqueous layer with three 50 ml. portions of ether. Cool the combined ether extracts by the addition of ice, and add cautiously 100 ml. of 25 per cent, sodium hydroxide solution run off the aqueous layer and repeat the... 

The following is a modification of the process described and gives quite satisfactory results. Wash the crude mixture of benzonitrile and dibromopentane with sodium carbonate solution until the latter remains alkaline, and then with water. Distil it under reduced pressure and collect the fraction boiling up to 120°/18 mm. Dissolve this in twice its volume of light petroleum, b.p. 40-60°, which has previously been shaken with small volumes of concentrated sulphuric acid until the acid remains colourless. Shake the solution with 6 per cent, of its volume of concentrated sulphuric acid, allow to settle, and run ofi the sulphuric acid layer repeat the extraction until the acid is colourless or almost colourless. Wash successively with water, sodium carbonate solution and water, dry over anhydrous calcium chloride or calcium sulphate, and distil off the solvent. Distil the residue under diminished pressure and collect the 1 6-dibromopentane at 98- 100°/13 mm. 

Benzene. Add 0 5 ml. of benzene slowly and with shaking and cooling to a mixture of 4 ml. each of concentrated sulphuric and nitric acids. Heat the mixture carefully until it just boils, cool and pour into excess of cold water. Filter oflF the precipitate, wash it free from acid and recrystalhse it from dilute alcohol. m-Dinitrobenzene m.p. 90°, is formed. 

Place 18 g. (12 ml.) of fuming nitric acid, sp. gr. 1 5, and 30 g. (16-5 ml.) of concentrated sulphuric acid and a few fragments of broken glass in a 250 or 500 ml. round-bottomed flask. Add gradually, in small portions, 14 g. of p-nitrotoluene do not allow the temperature to rise above 50 and cool the flask, if necessary, by immersion in cold water. Place a small funnel in the mouth of the flask and heat on a water bath at 90-95° for 30 minutes. Allow to cool almost to the laboratory temperature and pour the reaction mixture slowly into about 500 ml. of ice water containing a few small pieces of ice. Filter the crude dinitrotoluene through a Buchner funnel at the pump, wash it thoroughly with cold water, and drain as completely as possible. RecrystalUse from the minimum volume of hot methyl alcohol (flask, reflux condenser, and water bath experimental details as in Section IV,12). The yield of pure 2 4-dinitrotoluene, m.p. 71°, is 12 -5 g. 

Commercial benzene may be purified by shaking repeatedly with 10 per cent, of its volume of concentrated sulphuric acid until the acid layer is almost colourless, then washing successively with cold water, 10 per cent, sodium carbonate solution and water, and drying with anhydrous calcium chloride or inagnosiuin sulphate. Distillation then yields pure benzene. 

Heat a mixture of 15 g. of p-nitroacetanilide and 75 ml. of 70 per cent, sulphuric acid (1) under a reflux water condenser for 20-30 minutes or until a test sample remains clear upon dilution with 2-3 times its volume of water. The p-nitroaniline is now present in the hquid as the sulphate. Pour the clear hot solution into 500 ml. of cold water and precipitate the p-nitroanihne by adding excess of 10 per cent, sodium hydroxide solution or of concentrated ammonia solution. When cold (cool the mixture in ice water, if necessary), filter the yellow crystalline precipitate at the pump, wash it well with water, and drain thoroughly. Recrystallise it from a mixture of equal volumes of rectified (or methylated) spirit and water or from hot water. Filter, wash and dry. The yield of p-nitroanihne, m.p, 148°, is 11 g. 

Dissolve 1 g. of the secondary amine in 3-5 ml. of dilute hydrochloric acid or of alcohol (in the latter case, add 1 ml. of concentrated hydrochloric acid). Cool to about 5° and add 4-5 ml. of 10 per cent, sodium nitrite solution, and allow to stand for 5 minutes. Add 10 ml. of water, transfer to a small separatory funnel and extract the oil with about 20 ml. of ether. Wash the ethereal extract successively with water, dilute sodium hydroxide solution and water. Remove the ether on a previously warmed water bath no flames should be present in the vicinity. Apply Liebermann s nitroso reaction to the residual oil or solid thus. Place 1 drop or 0 01-0 02 g. of the nitroso compovmd in a dry test-tube, add 0 05 g. of phenol and warm together for 20 seconds cool, and add 1 ml. of concentrated sulphuric acid. An intense green (or greenish-blue) colouration will be developed, which changes to pale red upon pouring into 30-50 ml. of cold water the colour becomes deep blue or green upon adding excess of sodium hydroxide solution. 

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