Sulfate

“ Its usual form of occurrence is in combination with the metals to form sulfids, or with oxygen and a metal to form sulfates. Sulfur and iron combine to form iron pyrites or iron disulfid (FeS2) , while sulfur, oxygen, and calcium are found in gypsum, an important fertilizing compound.
Sulfur plays an important part in the nourishment of plants, being found in them both as sulfuric acid and in organic compounds. Methods for estimating the sulfur in both forms will be found in another part of this manual.
9. Hydrogen is a colorless, invisible gas, without taste or smell. ”

“ SAMPLE PREPARATION: 5. Put the two filters from the sampler into separate, clean vials. Discard the backup pads. Add 10.0 mL eluent to each vial and let stand, with occasional vigorous shaking, for 30 min. NIOSH Manual of Analytical Methods (NMAM) , Fourth Edition, 8/15/94 SULFUR DIOXIDE: METHOD 6004, Issue 2, dated 15 August 1994 - Page 3 of 4 NOTE: The SO 2 collected on the treated (back) filter is present as sulfite, which oxidizes in air slowly (over several weeks) to sulfate. ”

“ Sulphur is now generally regarded as emanating from the stage of intermittent lethargy of a volcano, and the sulphides of iron, copper, arsenic, zinc, selenium, etc., fall in the same category as sulphur; they are secondary, not primary, formations. In the stage further off we have the host of sulphates produced by the oxidation of the sulphur into sulphuric acid, and its subsequent reaction on the metals and earths with which it becomes associated. ”

“ As it cools to the atmospheric temperature, beautiful crystalline needles form, which may be washed sufficiently with cold alcohol, or even tepid water. The usual impurities of the sulphur, which are carbonate and sulphate of zinc, oxide and sulphuret of iron, sulphuret of arsenic and silica, will remain unaffected by the volatile oil, and may be separately eliminated by the curious, though such separation is of little practical importance. ”

“ Precipitation with sulphur dioxide and sulphuretted hydrogen proceeds much more rapidly, and has been adopted at many works. Sulphur dioxide, generated by burning sulphur, is forced into the solution under pressure, where it interacts with any free chlorine present to form hydrochloric and sulphuric acids. Sulphuretted hydrogen, obtained by treating iron sulphide or a coarse matte with dilute sulphuric acid, is forced in similarly. The gold is precipitated as the sulphide, together with any arsenic, antimony, copper, silver and lead which may be present. ”

“ The white vapour is the oxygenated sulphur, which assumes the form of an elastic fluid of a pungent and offensive smell, and is a powerful acid. Here you see a chemical combination of oxygen and sulphur, producing a true gas, which would continue such under the pressure and at the temperature of the atmosphere, if it did not unite with the water in the plate, to which it imparts its acid taste, and all its acid properties.—You see, now, with what curious effects the combustion of sulphur is attended. ”

“ From the decomposition of the sulphate of iron which takes place, a vast quantity of sulphuric acid must be generated, which, reacting on the different bases of magnesia, lime, etc., contained in the strata, forms those sulphates so prevalent in the higher or pyritous beds of the Lias; the oxide of iron being at the same time more or less completely separated. By this means the mineral waters, which are probably mere brine-springs at the greatest depths, acquire additional medicinal qualities as they ascend to the places whence they flow. ”

“ Five parts of a luminous sulphide of an alkaline earth, 10 of fluorspar, cryolite, or other similar fluoride, 1 of barium borate; powdered, mixed, made into a cream with water, painted on the glass or stone article, dried, and fired in the usual way for enamels. If the article contains an oxide of iron, lead, or other metal, it must be first glazed with ground felspar, silica, lime phosphate, or clay, to keep the sulphur of the sulphide from combining with the metal. ”

“ Sulphuric acid will only evolve sulphuretted hydrogen from those sulphides which contain a metal capable of decomposing the acid with the evolution of hydrogen. Thus zinc, iron, calcium, magnesium, manganese, potassium, sodium, &c., form sulphides which evolve sulphuretted hydrogen when treated with sulphuric acid, and the metals themselves evolve hydrogen with acids. ”

“ Like other acids, it never occurs in nature in a pure state, for it can no sooner be formed than it unites with earths (31) , alkalies (42) , or metals, and forms, with them, several well-known salts, which have the name of sulphats. Thus alabaster (192) and Epsom salts (199) are respectively formed by an union of sulphuric acid with lime and magnesia, and are denominated by chemists sulphat of lime and sulphat of magnesia. In like manner, blue vitriol (209) is sulphat of copper; green vitriol (208) , sulphat of iron; and white vitriol (210) , sulphat of zinc. ”

“ Combined with metals (sulphides) , it is common in all mineral districts. Iron pyrites (FeS2) is the most abundant source of this element. Sulphates, such as gypsum, are fairly common, but have no value so far as the sulphur in them is concerned. In coal it exists as an impurity, occurring partly as a constituent of organic compounds.
Sulphur, whether free or combined with metals, forms, on burning, sulphurous oxide (SO2) , which by the action of oxidising agents and water is converted into sulphuric acid. ”

“ Nitrogen gas occurs especially in hot sulphur springs, with carburetted hydrogen, oxygen, and sulphuretted hydrogen as lesser gaseous ingredients. Mineral springs are classified as follows, according to the salts from which they derive their specific importance. 1. Chalybeate or Ferruginous Springs. The distinguishing characteristic of these is the presence of iron dissolved as a bicarbonate, or in the inferior ones as a sulphate. Their other ingredients are bicarbonates of manganese, soda, lime, and magnesia, chloride of sodium, sulphate of soda and of potash, &c. ”

“ What is sulphuric oxide, and what relation does it bear to sulphur?
5. A mineral contains 20.7 per cent. of water, 32.4 per cent. of lime, and 18.6 per cent. of sulphur. What is its probable composition? What experiment would you try to determine the accuracy of your conclusion?
SELENIUM
occurs in nature combined with copper, mercury, and lead, in certain rare minerals. In small quantities it is found in many ores. It is detected in solution by the red precipitate produced on boiling the acid solution with sodium sulphite. This reaction is used for its determination. ”

“ Sulphurous Acid, H2SO3.—The reagent used may be regarded as a saturated solution of sulphur dioxide in water. It may be purchased, and keeps for a long time. It may be made by heating copper with sulphuric acid and passing the gas formed into water. The heat should be withdrawn when the gas is coming off freely. It is used as a reducing agent, and should not be diluted.
Sulphuric Acid, H2SO4. (Sp. gr. 1.84, containing 96 per cent. of real acid, H2SO4.) —This acid forms insoluble sulphates with salts of lead, strontium, and barium. ”

“ Much sulphur is found in this earth, together with various mineral salts, as hydro-chlorate of soda, sulphate of soda—sulphates of lime and magnesia—carbonate of iron—silex—alum—bitumen, &c.
Besides the general effects of hot, warm, and tepid baths of mineral water, the mud-baths exhibit effects peculiar to themselves. They may be taken at a higher temperature than water-baths, without inconvenience. They are never employed cold. ”

“ When heated to the temperature of 560° F. it takes fire, burns away with a dull blue flame of a suffocating odour, and leaves no residuum. When more strongly heated, sulphur burns with a vivid white flame. It is not affected by air or water.
Sulphur is an abundant product of nature; existing sometimes pure or merely mixed, and at others in intimate chemical combination with oxygen, and various metals, forming sulphates and sulphurets. See Ores of Copper, Iron, Lead, &c., under these metals. ”

“ Sulphur, sometimes in the form of milk of sulphur, was used; in another, the common flower of sulphur; sometimes acetate of lead, at other times oxide of that metal. In all the chemical change is the same, namely, the solution of the metal entering into the filament by absorption, there unites with sulphur, forming a sulphuret of the material used. Hair is porous; sulphur exists in hair of all colours, but is in excess in red and blonde hair. ”

“ Sulphur Compounds.—Ferrous sulphide, FeS, results from the direct union of its elements, best by stirring molten sulphur with a white-hot iron rod, when the sulphide drops to the bottom of the crucible. It then forms a yellowish crystalline mass, which readily dissolves in acids with the liberation of sulphuretted hydrogen. Heated in air it at first partially oxidizes to ferrous sulphate, and at higher temperatures it yields sulphur dioxide and ferric oxide. It is unaltered by ignition in hydrogen. An amorphous form results when a mixture of iron filings and sulphur are triturated with water. ”

“ In some cases it really appears that a complete account of the accumulation of the substances is very difficult to collect, except we call in successively the solvent powers of water and heat. The formation of sulphuret is obviously one of the most important of all the facts requiring explanation in mineral veins, because a very large proportion of metallic ores (tin is the principal exception) appears in this state. Heat, by sublimation, sulphuretted hydrogen, by decomposition of metallic salts, may give us the sulphuret ”

“ But the Sulphur of Antimony which is vehemently vomitive, and the strongly scented Anodyne Sulphur of Vitriol inclines me to think that not only Mineral Sulphurs differ from Vegetable ones, but also from one another, retaining much of the nature of their Concretes. The salts of metals, and of some sort of minerals, You will easily guesse by the Doubts I formerly express’d, whether metals have any salt at all, that I have not been so happy as yet to see, perhaps not for want of curiosity. ”

“ SULPHURETTED HYDROGEN, is a gas, composed of one part of hydrogen and sixteen parts of sulphur, by weight. Its specific gravity is 1·1912, compared to air = 1·0000. It is the active constituent of the sulphureous mineral waters. When breathed, it is very deleterious to animal life; and being nearly twice as dense as air, it may be poured from its generating bottle into cavities; a scheme successfully employed by M. Thenard to destroy rats in their holes.
SULPHURIC ACID, Vitriolic Acid, or Oil of Vitriol (Acid sulfurique, Fr.; Schwefelsaüre, Germ.) ”

“ Sul′phūretted, having sulphur in combination; Sulphū′ric, pertaining to, or obtained from, sulphur: denoting a certain well-known strong acid, formerly called oil of vitriol; Sul′phūrous, pertaining to, resembling, or containing sulphur: denoting the pungent acid given out when sulphur is burned in air; Sul′phury, partaking of the qualities of sulphur.—Sulphuretted hydrogen, a compound of sulphur and hydrogen, stinking and noxious; Sulphurous acid, an acid formed by one equivalent of sulphur combined with two of oxygen. [L. sulphur; said to be conn. with Sans. çulvāri.] ”

“ Place some sulphur in a little copper ladle attached to a wire, and called a deflagrating spoon, passed through a round piece of zinc or brass plate and cork, so that the latter acts as an adjusting arrangement to fix the wire at any point required. The combustion of the sulphur, previously feeble, now assumes a remarkable intensity, and a peculiar coloured light is generated, whilst the sulphur unites with the oxygen, and forms sulphurous acid gas. It produces, in fact, the same gas which is formed by burning an ordinary sulphur match. ”

“ Sulphates may be detected by heating the salt mixed with sodium carbonate on charcoal in the reducing flame of the blowpipe; sodium sulphide is thus formed, and may be identified by the black stain produced if the mass be transferred to a silver coin and then moistened. In solution. sulphates are always detected and estimated by the formation of a white precipitate of barium sulphate, insoluble in water and all the common reagents. Manufacture.-The first step in its manufacture is the combustion of sulphur. ”

“ The reaction between sulphide of iron and sulphuric acid takes place at the ordinary temperature, and is accompanied by just as small a development of heat as in the liberation of hydrogen itself, FeS + H2SO4 = FeSO4 + H2S. [15]
In nature sulphuretted hydrogen is formed in many ways. The most usual mode of its formation is by the decomposition of albuminous substances containing sulphur, as mentioned above. Another method is by the reducing action of organic matter on sulphates, and by the action of water and carbonic acid on the sulphides formed by this reduction. ”

“ By applying these principles to the nomenclature of neutral salts, we give a common term to all the neutral salts arising from the combination of one acid, and distinguish the species by adding the name of the salifiable base. Thus, all the neutral salts having sulphuric acid in their composition are named sulphats; those formed by the phosphoric acid, phosphats, &c. The species being distinguished by the names of the salifiable bases gives us sulphat of potash, sulphat of soda, sulphat of ammoniac, sulphat of lime, sulphat of iron, &c. ”

“ SULPHURIC ACID, or Oil of Vitriol, H2SO4, perhaps the most important of all chemicals, both on account of the large quantities made in all industrial countries and of the multifarious uses to which it is put. It is not found in nature in the free state to any extent, and although enormous quantities of its salts, especially calcium and barium sulphate, are found in many localities, the free acid is never prepared from these salts, as it is more easily obtainable in another way, viz. by burning sulphur or a sulphide, and combining the sulphur dioxide thus formed with more oxygen (and water) . ”