Alkalis sulphur compounds

H. E. Schone, and many others. The corresponding soda-liver of sulphur has been investigated by L. N. Vauquelin, E. Filhol, and J. B. Senderens, etc. The results are discussed in connection with the alkali sulphides, and polysulphides. Liver of sulphur is not a chemical individual, but rather a mixture of many sulphur compounds of the alkalies. 

What place do these metals occupy in the electrochemical series How do they react with acids and alkalies What compounds form when vanadium, niobium, and tantalum react with oxygen, the halogens, and sulphur ... 

Sulphur compounds, (a) Disulphides can be purified by extracting acidic and basic impurities with aqueous base or acid, respectively. However, they are somewhat sensitive to strong alkali which slowly cleaves the disulphide bond. The lower-melting members can be fractionally distilled under vacuum. The high members can be recrystallised from alcohol, toluene or glacial acetic acid. 

A rapid volumetric method for the determination of sulphur is as follows 2 The sulphur is dissolved in a known volume of hot standard sodium hydroxide solution and after cooling is oxidised to sulphate by the addition of hydrogen peroxide the excess of alkali is then titrated with standard acid.3 The method is applicable to gases containing any common sulphur compound except thiophen (e.g. coke oven gas).4... 

Metallic substances, acids, alkalis, sulphur, and resins, he was able to show, liked to combine with some substances in preference to others. Matter, it seemed, liked to commit to relationships, but only until something better came along. Thus Geoffroy was able to show that the strength of the affinity, rapport, or attraction of certain bodies for certain reagents varied from substance to substance. When two substances combined, the addition of a third, with more affinity for one of the substances than the other, caused a separation from the unpreferred substance in the compound. But what... 

Kepen Any of several sulphur compounds, liver-colored, made by fueing sulfur or a sulphide with an alkali metal compound or metallic oxide as hepar antlmonii Umpure antimony and potassium sulphide heoer calcis Ccelcium sulphide) heoer eulphurus or liver of sulphur (impure potassium suli lde). 

It may be concluded from the data that the severe fouling experienced in RDF fuelled boiler plant, is due to the volatilisation of alkali metals from the fuel bed. Oxides in reaction with acidic oxides of sulphur, or sulphates, are extremely sticky at the temperatures encountered in the equipment and tend to adhere to the cooler heat transfer surfaces. In coal burning, the alkali metal compounds constitute a sticky matrix which retains the impinging fly-ash, whereas in RDF combustion the concentration of alkali salts in the flue gas is so high that the rate of condensation exceeds the rate of fly ash retention. 

Petroleum and synthetic products. Crude petroleum products contain reduced sulphur compounds and reactive unsaturated compounds which are amenable to treatment with H2O2 [276]. Various additives used to enhance removal are alkali hydroxides [277], cation exchange resins [278] and surfactants [279], products being removed by distillation or extraction [280]. Sometimes, hydrogen peroxide can be... 

P Keto esters (t.g., ethyl ocetoacetate) are soluble in solutions of caustic alkalis but not in sodium carbonate solution. They give colours with freshly prepared ferric chloride solution a little alcohol should be added to bring the ester into solution. Sodium ethoxide solution reacts to yield sodio compounds, which usually crystallise out in the cold. Phenylhydrazine yields pyrazolones. They are hydrolysed by boiling sulphuric acid to the Corresponding ketones, which can be identified as usual (Section 111,74). 

Once the presence of a sulphonate group has been estabhshed (and, if possible, the phenol isolated), the compound may be characterised by the preparation of a derivative. It must be remembered that both sulphoxides RSOR and sulpJiones RSOjR yield sulphur dioxide on fusion with caustic alkali and acidification. 

Esters of sulphuric acid. These compounds are generally water insoluble liquids and are saponified by boiling with water or dilute alkali to the corresponding alcohols and sulphuric acid ... 

Hot oleum (>50°C), strong alkalis, fluoride solutions, sulphur trioxide Strong alkalis, especially >54°C, distilled water >82°C, hydrofluoric acid, acid fluorides, hot concentrated phosphoric acid, lithium compounds >1 77°C, severe shock or impact applications Strong oxidizers, very strong solvents... 

Glycerol, ethylene glycol, benzaldehyde, sulphuric acid Acetylene, oxalic acid, tartaric acid, fulminic acid (produced in ethanol-nitric acid mixtures), ammonium compounds See alkali metals (above)... 

Reactions of contaminants in the fuel or air in the combustion zone can result in the formation of compounds which can condense as molten salts onto cooler components in the system. This type of process can occur when fuels containing sulphur or vanadium are burnt. In the case of sulphur contaminants, alkali sulphates form by reactions with sodium which may also be present in the fuel or in the combustion air, and for vanadium-containing fuels low-melting-point sodium vanadates or vanadium pentoxide are produced, particularly when burning residual oils high in vanadium. Attack by molten salts has many features in common which will be illustrated for the alkali-sulphate-induced attack, but which will be subsequently shown to be relevant to the case of vanadate attack. 

Molybdates yield sparingly soluble orange-yellow molybdyl oxinate with oxine solution the pH of the solution should be between the limits 3.3-7.6. The complex differs from other oxinates in being insoluble in organic solvents and in many concentrated inorganic acids. The freshly precipitated compound dissolves only in concentrated sulphuric acid and in hot solutions of caustic alkalis. This determination is of particular interest, as it allows a complete separation of molybdenum from rhenium. 

Discussion. This gravimetric determination depends upon the separation and weighing as elementary selenium or tellurium (or as tellurium dioxide). Alkali selenites and selenious acid are reduced in hydrochloric acid solution with sulphur dioxide, hydroxylammonium chloride, hydrazinium sulphate or hydrazine hydrate. Alkali selenates and selenic acid are not reduced by sulphur dioxide alone, but are readily reduced by a saturated solution of sulphur dioxide in concentrated hydrochloric acid. In working with selenium it must be remembered that appreciable amounts of the element may be lost on warming strong hydrochloric acid solutions of its compounds if dilute acid solutions (concentration <6M) are heated at temperatures below 100 °C the loss is negligible. 

This class of aziridine-forming reaction includes the first reaction reported to afford aziridines. In 1888 Gabriel reported that aziridines could be prepared in a two-step process, by chlorination of ethanolamines with thionyl chloride, followed by alkali-induced cyclization [75]. Wenker subsequently reported that heating of 600 g of ethanolamine with more than 1 kg of 96 % sulfuric acid at high temperature produced P-aminoethyl sulphuric acid 282 g of it was distilled from aqueous base to give 23 g of aziridine itself, the first preparation of the parent compound in a pure condition [76]. Though there is no evidence to substantiate the hypothesis, the intermediate in these reactions is perhaps a cyclic sulfamidate (Scheme 4.51). 

Air contaminants Gases sulphur oxides, halogen compounds Mists aerosols, salt, alkalies Particulates sand, dust, grease... 

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