It is occasionally used as a chlorine carrier.
It combines directly with fluorine at Ordinary temperature, and with chlorine, bromine and sulphur on heating.
For example, compounds of oxygen are oxides, of chlorine, chlorides, and so on.
Cobalt chloride, CoC1 2, in the anhydrous state, is formed by burning the metal in chlorine or by heating the sulphide in a current of the same gas.
We may suppose that in the formation of gaseous hydrochloric acid from gaseous chlorine and hydrogen, according to the equation H2 +C1 2 = HCI+HC1, a certain amount of energy is expended in separating the atoms of hydrogen in the hydrogen molecule, and the atoms of chlorine in the chlorine molecule, from each other; but that heat is developed by the combination of the hydrogen atoms with the chlorine atoms, and that, as more energy is developed by the union of the atoms of hydrogen and chlorine than is expended in separating the hydrogen atoms from each other and the chlorine atoms from one another, the result of the action of the two elements upon each other is the development of heat, - the amount finally developed in the reaction being the difference between that absorbed in decomposing the elementary molecules and that developed by the combination of the atoms of chlorine and hydrogen.
The tetrachloride, SC14, is formed by saturating S 2 C1 2 with chlorine at - 22° C. (Michaelis, Ann., 1873, 170, p. 1).
The sesquichloride, Ru 2 C1 6, is formed when a mixture of chlorine and carbon monoxide is passed over finely divided ruthenium heated to 350° C. (Joly, Comptes rendus, 1892, 114, p. 291).
The per-ruthenate, KRuO 4, formed by the action of chlorine on the ruthenate, or of alkalis on the peroxide at 50° C., is a black crystalline solid which is stable in dry air but decomposes when heated strongly.
Soc., 1903, p. 420); and by the action of chlorine monoxide on sulphur at low temperature.
Molybdenum combines with the halogen elements in varying proportions, forming with chlorine a di-, tri-, tetraand penta-chloride, and similar compounds with bromine and iodine.
Solutions of persulphates in the cold give no precipitate with barium chloride, but when warmed barium sulphate is precipitated with simultaneous liberation of chlorine: K 2 S 2 0 8 + BaC1 2 = BaSO 4 + K 2 SO 4 + C1 2.
The following, however, are negative towards the remaining elements which are more or less positive:-Fluorine, chlorine, bromine, iodine, oxygen, sulphur, selenium, tellurium.
By replacing the chlorine in the imido-chloride by an oxyalkyl group we obtain the imido-ethers, R C(OR') :NH; and by an amino group, the amidines, R C(NH 2): NH.
For instance, 35'45 parts of chlorine and 79.96 parts of bromine combine with 107.93 parts of silver; and when chlorine and bromine unite it is in the proportion of 35'45 parts of the former to 79.96 parts of the latter.
Molybdenum pentachloride, MoC1 5r is obtained when molybdenum is gently heated in dry chlorine (L.
For example, one volume of oxygen combined with two of hydrogen to form two volumes of steam, three volumes of hydrogen combined with one of nitrogen to give two volumes of ammonia, one volume of hydrogen combined with one of chlorine to give two volumes of hydrochloric acid.
Silver chloride, for example, in whatever manner it may be prepared, invariably consists of chlorine and silver in the proportions by weight of 35'45 parts of the former and 107.93 of the latter.
It is a brown-black powder soluble in hydrochloric acid, chlorine being simultaneously liberated.
Phenol is characterized by the readiness with which it forms substitution products; chlorine and bromine, for example, react readily with phenol, forming orthoand parachlorand -bromphenol, and, by further action, trichlorand tribrom-phenol.
By heating the metal with chlorine, germanic chloride, GeCl4, is obtained as a colourless fuming liquid boiling at 86-87° C., it is decomposed by water forming a hydrated germanium dioxide.
It combines directly with chlorine to form sulphuryl chloride and also with many metallic peroxides, converting them into sulphates.
Thus the chlorine oxyacids enumerated above form salts named respectively hypochlorites, chlorites, chlorates and perchlorates.
This difference in behaviour of the three elements, chlorine, bromine and iodine, which in many respects exhibit considerable resemblance, may be explained in the following manner.
Thus, chlorine enters into reaction with hydrogen, and removes hydrogen from hydrogenized bodies, far more readily than bromine; and hydrochloric acid is a far more stable substance than hydrobromic acid, hydriodic acid being greatly inferior even to hydrobromic acid in stability.
Hydrochloric acid was carefully investigated at about this time by Davy, Faraday and Gay Lussac, its composition and the elementary nature of chlorine being thereby established.
Balard discovered chlorine monoxide in 1834, investigating its properties and reactions; and his observations on hypochlorous acid and hypochlorites led him to conclude that " bleaching-powder " or " chloride of lime " was a compound or mixture in equimolecular proportions of calcium chloride and hypochlorite, with a little calcium hydrate.
Thus from the acid-amides, which we have seen to be closely related to the acids themselves, we obtain, by replacing the carbonyl oxygen by chlorine, the acidamido-chlorides, R CC1 2 NH 2, from which are derived the imido-chlorides, R CC1:NH, by loss of one molecule of hydrochloric acid.
Iodine unites with silver in the proportion of 126.97 parts to 107.93 parts of the latter, but it combines with chlorine in two proportions, viz.
Thus, in the production of hydrochloric acid from hydrogen and chlorine 22,000 calories are developed; in the production of hydrobromic acid from hydrogen and bromine, however, only 8440 caloriesare developed; and in the formation of hydriodic acid from hydrogen and iodine 6040 calories are absorbed.
Again, when tungsten hexachloride is converted into vapour it is decomposed into chlorine and a pentachloride, having a normal vapour density, but as in the majority of its compounds tungsten acts as a hexad, we apparently must regard its pentachloride as a compound in which an odd number of free affinities are disengaged.
The chemical analogy of this substance to chlorine was quickly perceived, especially after its investigation by Davy and Gay Lussac. Cyanogen, a compound which in combination behaved very similarly to chlorine and iodine, was isolated in 1815 by Gay Lussac. This discovery of the first of the then-styled " compound radicals " exerted great influence on the prevailing views of chemical composition.
Serullas and Roscoe; Davy and Stadion investigated chlorine peroxide, formed by treating potassium chlorate with sulphuric acid.
It is frequently used as an "antichlor," since in presence of water it has the power of converting chlorine into hydrochloric acid: SO 2 + C12 + 2H 2 0 = 2HC1 + H 2 SO 4.
The elements are usually divided into two classes, the metallic and the non-metallic elements; the following are classed as non-metals, and the remainder as metals: Of these hydrogen, chlorine, fluorine, oxygen, nitrogen, argon, neon, krypton, xenon and helium are gases, bromine is a liquid, and the remainder are solids.
The combination, as it is ordinarily termed, of chlorine with hydrogen, and the displacement of iodine in potassium iodide by the action of chlorine, may be cited as examples; if these reactions are represented, as such reactions very commonly are, by equations which merely express the relative weights of the bodies which enter into reaction, and of the products, thus Cl = HC1 Hydrogen.
The action of chlorine upon diand tri-oxybenzenes has been carefully investigated by Th.
Boron chloride BC1 3 results when amorphous boron is heated in chlorine gas, or more readily, on passing a stream of chlorine over a heated mixture of boron trioxide and charcoal, the volatile product being condensed in a tube surrounded by a freezing mixture.
Sulphur chloride, S2C12, is obtained as a by-product in the manufacture of carbon tetrachloride from carbon bisulphide and chlorine, and may also be prepared on the small scale by distilling sulphur in a chlorine gas, or by the action of sulphur on sulphuryl chloride in the presence of aluminium chloride (0.
Thus the equation Cl 2 -1-2KI, Aq=2KC1, Aq+12+52400 cal., or (C12) +2KI, Aq =2KC1, Aq+-I-52400 cal., would express that when gaseous chlorine acts on a solution of potassium iodide, with separation of solid iodine, 52400 calories are evolved.
The residue is then fused with caustic potash and nitre, dissolved in water, saturated with chlorine and distilled on the water-bath in a current of chlorine.
The peroxide, Ru04, is formed when a solution of potassium ruthenate is decomposed by chlorine, or by oxidizing ruthenium compounds with potassium chlorate and hydrochloric acid, or with potassium permanganate and sulphuric acid.
Held synthesized the acid from ethyl chlor-acetoacetate (from chlorine and acetoacetic ester) by heating with potassium cyanide and saponifying the resulting nitrile.
By the action of phosphorus pentachloride, the hydroxyl group is replaced by chlorine.
Sulphur chloride dissolves sulphur with great readiness and is consequently used largely for vulcanizing rubber; it also dissolves chlorine.
in the proportion of 126.97 parts either to 35'45 or to three times 35'45 parts of chlorine.
In the formation of gaseous hydrobromic acid from liquid bromine and gaseous hydrogen H2+Br2=HBr+HBr, in addition to the energy expended in decomposing the hydrogen and bromine molecules, energy is also expended in converting the liquid bromine into the gaseous condition, and probably less heat is developed by the combination of bromine and hydrogen than by the combination of chlorine and hydrogen, so that the amount of heat finally developed is much less than is developed in the formation of hydrochloric acid.
In general, the rupture occurs between a keto group (CO) and a keto-chloride group (CC1 2), into which two adjacent carbon atoms of the ring are converted by the oxidizing and substituting action of chlorine.
The heptachlor compound when treated with chlorine water gives trichloraceto-pentachlorbutyric acid (6), which is hydrolysed by alkalis to chloroform and pentachlorglutaric acid (7), and is converted by boiling water into tetrachlor-diketo-Rpentene (8).
This compound is converted by chlorine water into octachloracetylacetone (3) by methyl alcohol into the ester of dichlormalonic acid and tetrachioracetone (4); whilst ammonia gives dichloracetamide (5) (Th.
CC13+C02 O?OIi O / O / (4) Cl2HC CO CHCl2+CH302C CCl2C02CH3 (5) Cl2HC CONH2 Cl (z) (2) When phenol is oxidized in acid solution by chlorine, tetrachlorquinone is obtained, a compound also obtainable from hydroquinone.
Chlorimetry (1824), alkalimetry (1828), and the volumetric determination of silver and chlorine (1832) were worked out by Gay Lussac; but although the advantages of the method were patent, it received recognition very slowly.
Chlorine, bromine, and iodine, each recognizable by its colour and odour, result from decomposable haloids; iodine forms also a black sublimate.
The elements which play important parts in organic compounds are carbon, hydrogen, nitrogen, chlorine, bromine, iodine, sulphur, phosphorus and oxygen.
Horbaczewski's method, which consists in boiling the substance with strong potash, saturating the cold solution` with chlorine, adding hydrochloric acid, and boiling till no more chlorine is liberated, and then testing for sulphuric acid with barium chloride.
In the first method the substance, mixed with quicklime free from chlorine, is heated in a tube closed at one end in a combustion furnace.
To take an example: 38 parts of indium combine with 35.4 parts of chlorine; hence, if the formula of the chloride be InCI, InC1 2 or InC1 3, indium has the atomic weights 38, 76 or 114.
This is shown in the case of the chloracetic acids: According to van 't Hoff the substitution of chlorine atoms into a methyl group occasions the following increments: The introduction of chlorine, however, may involve a fall in the boiling-point, as is recorded by Henry in the case of the chlorinated acetonitriles: NC CH 3.
Thus bromine and iodine replace chlorine with increments of about 22° and 50° respectively.
The thermal effects of the halogens are: chlorine =15.13 calories, bromine = 7.68; iodine = - 4.25 calories.
The colour produced is generally of a greenish shade; for example, nitrosobenzene is green when fused or in solution (when crystalline, it is colourless), and dinitrosoresorcin has been employed as a dyestuff under the names " solid green " and " chlorine."
molecular weight, is constant for isomers, and that two atoms of hydrogen were equal to one of carbon, three to one of oxygen, and seven to one of chlorine; but these ratios were by no means constant, and afforded practically no criteria as to the molecular weight of any substance.
The chlorine atom in this compound is replaced by the cyano-group, which is then reduced to the CH 2 NH 2.
Chlorine azide, C1 N 31 was discovered by F.
Journ., 1811, 8, p. 302), and obtained by the action of chlorine or sodium hypochlorite on ammonium chloride, or by the electrolysis of ammonium chloride solution, is a very volatile yellow oil.
Phys., 1850 , 28, p. 241) by the action of dry chlorine on silver nitrate: 4AgN03+2C12=4AgC1+2N205 +02.
Nitrosyl chloride, NOC1, is obtained by the direct union of nitric oxide with chlorine; or by distilling a mixture of concentrated nitric and hydrochloric acids, passing the resulting gases into concentrated sulphuric acid and heating the so-formed nitrosyl hydrogen sulphate with dry salt: HN03+3HCl=NOC1+C12 +H 2 O; NOC1 + H2S04 = HCl + NO SO 4 H; NO SO 4 H + NaC1 = Noci+NaHS04 (W.
Now this ratio is the same as that which gives the relative chemical equivalents of hydrogen and copper, for r gramme of hydrogen and 31.8 grammes of copper unite chemically with the same weight of any acid radicle such as chlorine or the sulphuric group, SO 4.
Thus the hydroxyl mentioned above decomposes into water and oxygen, and the chlorine produced by the electrolysis of a chloride may attack the metal of the anode.
A freedom of interchange is thus indicated between the opposite parts of the molecules of salts in solution, and it follows reasonably that with the solution of a single salt, say sodium chloride, continual interchanges go on between the sodium and chlorine parts of the different molecules.
It is necessary to point out that the dissociated ions of such a body as potassium chloride are not in the same condition as potassium and chlorine in the free state.
Thus neither a chlorate, which contains the ion C103, nor monochloracetic acid, shows the reactions of chlorine, though it is, of course, present in both substances; again, the sulphates do not answer to the usual tests which indicate the presence of sulphur as sulphide.
Silver chloride is a very insoluble substance, and here the amount in solution is still further reduced by the presence of excess of chlorine ions of the potassium salt.
Caoutchouc, like other "unsaturated" molecules, forms compounds with chlorine, bromine, iodine and sulphur.
It is a very stable compound, chlorine, concentrated nitric acid and hydriodic acid having no action upon it.
It is also obtained by passing chlorine into a suspension of lead oxide or carbonate, or of magnesia and lead sulphate, in water; or by treating the sesquioxide or red oxide with nitric acid.
It oxidizes a manganese salt (free from chlorine) in the presence of nitric acid to a permanganate; this is a very delicate test for manganese.
If a suspension of lead dichloride in hydrochloric acid be treated with chlorine gas, a solution of lead tetrachloride is obtained; by adding ammonium chloride ammonium plumbichloride, (NH 4) 2 PbC1 6, is precipitated, which on treatment with strong sulphuric acid yields lead tetrachloride, PbC1 4, as a translucent, yellow, highly refractive liquid.
It freezes at - 15° to a yellowish crystalline mass; on heating it loses chlorine and forms lead dichloride.
The residue is then dissolved in hot water, filtered, and the clear solution is mixed with very thin milk of lime so adjusted that it takes out one-half of the chlorine of the PbC1 2.
Nascent hydrogen reduces them to primary alcohols, and phosphorus pentachloride replaces the carbonyl oxygen by chlorine.
Columbium pentachloride, CbC1 5, is obtained in yellow needles when a mixture of the pentoxide and sugar charcoal is heated in a current of air-free chlorine.
It burns in oxygen at 170°, in chlorine at 180°, in bromine at 210°, in iodine at 260°, in sulphur at 50o, and combines with nitrogen at about iooa.
Uranous chloride, UC14, was first prepared by Peligot by heating an intimate mixture of the green oxide and charcoal to redness in a current of dry chlorine; it is obtained as sublimate of black-green metallic-looking octahedra.
The chloride is very hygroscopic. By heating in hydrogen it yields the trichloride, UC1 3, and by direct combination with chlorine the pentachloride, UC1 5.
Uranyl chloride, UO 2 C1 2, is a yellow crystalline mass formed when chlorine is passed over uranium dioxide at a red heat.
Stannic Chloride, SnC1 4, named by Andreas Libavius in 1605 Spiritus argenti vivi sublimate from its preparation by distilling tin or its amalgam with corrosive sublimate, and afterwards termed Spiritus fumans Libavii, is obtained by passing dry chlorine over granulated tin contained in a retort; the tetrachloride distils over as a heavy liquid, from which the excess of chlorine is easily removed by shaking with a small quantity of tin filings and re-distilling.
It is attacked rapidly by fluorine at ordinary temperature, and by chlorine when heated in a current of the gas.
It burns when brought into contact with chlorine, forming silicon chloride and hydrochloric acid.
Berzelius (Jahresb., 182 5, 4, p. 91) by the action of chlorine on silicon, and is also obtained when an intimate mixture of silica and carbon is heated in a stream of chlorine and the products of reaction fractionated.
The hexachloride, Si 2 C1 61 is formed when silicon chloride vapour is passed over strongly heated silicon; by the action of chlorine on the corresponding iodocompound, or by heating the iodo-compound with mercuric chloride (C. Friedel, Comptes rendus, 18 7 1, 73, P. 497).
The octochloride, Si 3 C1 8r is formed to the extent of about 2 to 1% in the action of chlorine on silicon (L.
It is decomposed by chlorine.
The latter reacts with chlorine to give silicon nonyl-chloride Si(C2H5)3 C2H4C1, which condenses with potassium acetate to give the acetic ester of silicon nonyl alcohol from which the alcohol (a camphor-smelling liquid) may be obtained by hydrolysis.
Chlorine.-All metals, when treated with chlorine gas at the proper temperatures, pass into chlorides.
In some cases the chlorine is taken up in two instalments, a lower chloride being produced first, to pass ultimately into a higher chloride.
Of the several products, the chlorides of gold and platinum (AuC13 and PtC1 4) are the only ones which when heated beyond their temperature of formation dissociate into metal and chlorine.
The ultimate chlorination product of copper, CuC1 2, when heated to redness, decomposes into the lower chloride, CuCI, and chlorine.
The following are readily volatilized in a current of chlorine, at a red heat: AiCI 3, CrC1 3, FeC1 3, the chlorides of aluminium, chromium, iron.
Hydriodic acid reduces it to hexamethylene" (cyclo-hexane or hexa-hydro-benzene); chlorine and bromine form substitution and addition products, but the action is slow unless some carrier such as iodine, molybdenum chloride or ferric chloride for chlorine, and aluminium bromide for bromine, be present.
CH 3; whilst chlorine and bromine give aß-dihaloid ethylbenzenes, e.g.
The following table shows the amounts of the chief constituents removed by certain crops in lb per acre: - Plants also remove from the soil silicon, sodium, chlorine, and other elements which are, nevertheless, found to be unessential for the growth and may therefore be neglected here.
13,336 of 1894) a rapidly rotating cathode is used in a chloride solution, a porous partition separating the tank into anode and cathode compartments, and the chlorine generated by electrolysis at the anode being recovered.
Both are easily removed by passing chlorine through the cold solution, to produce ferric and manganic salt, and then digesting the liquid with a washed precipitate of basic carbonate, produced from a small portion of the solution by means of sodium carbonate.
Thorpe), by heating to dull redness an intimate dry mixture of the oxide and ignited lamp-black in dry chlorine.
Wirthwein, the titanium mineral is fused with carbon in the electric furnace, the carbides treated with chlorine, and the titanium chloride condensed.
It oxidizes rapidly when exposed to air, and burns when heated in air, oxygen, chlorine, bromine or sulphur vapour.
The anhydrous chloride is formed by heating strontium or its monoxide in chlorine, or by heating the hydrated chloride in a current of hydrochloric acid gas.
When an alkaline chloride, say sodium chloride, is electrolysed with one electrode immersed in a porous cell, while caustic soda is formed at the cathode, chlorine is deposited at the anode.
The chlorine reacts with the caustic soda, forming sodium hypochlorite, and this in turn, with an excess of chlorine and at higher temperatures, becomes for the most part converted into chlorate, whilst any simultaneous electrolysis of a hydroxide or water and a chloride (so that hydroxyl and chlorine are simultaneously liberated at the anode) also produces oxygen-chlorine compounds direct.
It is obvious that, with suitable methods and apparatus, the electrolysis of alkaline chlorides may be made to yield chlorine, hypochlorites (bleaching liquors), chlorates or caustic alkali, but that great care must be exercised if any of these products is to be obtained pure and with economy.
In his process a current was passed through a tank divided into two or three cells by porous partitions, hoods and tubes were arranged to carry off chlorine and hydrogen respectively, and the whole was heated to r20° F.
Hypochlorites were made, at ordinary temperatures, and chlorates at higher temperatures, in a cell without a partition in which the cathode was placed horizontally immediately above the anode, to favour the mixing of the ascending chlorine with the descending caustic solution.
Oettel, using a 20% solution of potassium chloride, obtained the best yield of hypochlorite with a high current-density, but as soon as II% of bleaching chlorine (as hypochlorite) was present, the formation of chlorate commenced.
With high current-density, heating the solution tended to increase the proportion of chlorate to hypochlorite, but as the proportion of water decomposed is then higher, the amount of chlorine produced must be less and the total chlorine efficiency lower.
Kellner, who in 1886 patented the use of cathode (caustic soda) and anode (chlorine) liquors in the manufacture of cellulose from wood-fibre, and has since evolved many similar processes, has produced an apparatus that has been largely used.
A 10-12% solution of sodium chloride is caused to flow upwards through the apparatus and to overflow into troughs, by which it is conveyed (if necessary through a cooling apparatus) back to the circulating pump. Such a plant has been reported as giving 0.229 gallon of a liquor containing I% of available chlorine per kilowatt hour, or 0.171 gallon per e.h.p. hour.
Similarly, the formation of organic halogen products may be effected by electrolytic chlorine, as, for example, in the production of chloral by the gradual introduction of alcohol into an anode cell in which the electrolyte is a strong solution of potassium chloride.
The existence of acids not containing oxygen was, in itself, sufficient to overthrow this idea, but, although Berthollet had shown, in 1789, that sulphuretted hydrogen (or hydrosulphuric acid) contained no oxygen, Lavoisier's theory held its own until the researches of Davy, Gay-Lussac and Thenard on hydrochloric acid and chlorine, and of Gay-Lussac on hydrocyanic acid, established beyond all cavil that oxygen was not essential to acidic properties.
Phosphorus chlorides give acid chlorides, Rï¿½COï¿½C1, the hydroxyl group being replaced by chlorine, and acid anhydrides, (Rï¿½CO) 2 0, a molecule of water being split off between two carboxyl groups.
Chlorine oxidizes it to acetaldehyde, and under certain conditions chloral is formed.
The metal is soluble in solutions of chlorine, bromine, thiosulphates and cyanides; and also in solutions which generate chlorine, such as mixtures of hydrochloric acid with nitric acid, chromic acid, antimonious acid, peroxides and nitrates, and of nitric acid with a chloride.
It begins to decompose into gold and chlorine at 185°, the decomposition being complete at 230°; water decomposes it into gold and auric chloride.
It is also obtained by carefully evaporating a solution of the metal in chlorine water.
Gold dichloride, probably Au 2 C1 4, =Au.AuC1 4, aurous chloraurate, is said to be obtained as a dark-red mass by heating finely divided gold to 140°- 170° in chlorine.
- In this process moistened gold ores are treated with chlorine gas, the resulting gold chloride dissolved out with water, and the gold precipitated with ferrous sulphate, charcoal, sulphuretted hydrogen or otherwise.
Plattner, who suggested that the residues from certain mines at Reichenstein, in Silesia, should be treated with chlorine after the arsenical products had been extracted by roasting.
Three stages in the process are to be distinguished: (i.) calcination, to convert all the metals, except gold and silver, into oxides, which are unacted upon by chlorine; (ii.) chlorinating the gold and lixiviating the product; (iii.) precipitating the gold.
The auric chloride is, however, decomposed at the elevated temperature into finely divided metallic gold, which is then readily attacked by the chlorine gas.
Chlorine, generally prepared by the interaction of pyrolusite, salt and sulphuric acid, is led from a suitable generator beneath the false bottom, and rises through the moistened ore, which rests on a bed of broken quartz; the gold is thus converted into a soluble chloride, which is afterwards removed by washing with water.
There have also been introduced processes in which the chlorine is generated in the chloridizing vat, the reagents used being dilute solutions of bleaching powder and an acid.
Chlorine is generated within the barrel from sulphuric acid and chloride of lime.
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.
Miller's chlorine process is of any importance, this method, and the wet process of refining by sulphuric acid, together with the electrolytic process, being the only ones now practised.
The second process depends upon the fact that, if chlorine be led into the molten alloy, the base metals and the silver are converted into chlorides.
The bath is used at 65° to 70° C. (150° to 158° F.), and if free chlorine be evolved, which is known at once by its pungent smell, the temperature is raised, or more acid is added, to promote the solubility of the gold.
It is also formed by oxidizing bismuth trioxide suspended in caustic potash with chlorine, the pentoxide being formed simultaneously; oxidation and potassium ferricyanide simply gives the tetroxide (Hauser and Vanino, Zeit.
The dichloride, BiC1 2, is obtained as a brown crystalline powder by fusing the metal with the trichloride, or in a current of chlorine, or by heating the metal with calomel to 250°.
It is the final product of burning bismuth in an excess of chlorine.
They are both obtained by passing chlorine over tellurium, the product being separated by distillation (the tetrachloride is the less volatile).
The tetrachloride is a white crystalline solid which is formed by the action of chlorine on the dichloride or by sulphur chloride on the element.
Telluric acid, H2Te04, is obtained in the form of its salts when tellurium is fused with potassium carbonate and nitre, or by the oxidizing action of chlorine on a tellurite in alkaline solution.
Soc., 1909, 31, p. 20), by heating the double salt, TeBr4.2KBr, first in chlorine and finally in a current of hydrochloric acid to convert it into potassium chloride, obtained the value 127.55.
Tantalum pentachloride, TaC1 5, is obtained as light yellow needles by heating a mixture of the pentoxide and carbon in a current of chlorine.
The elements in addition to oxygen which exist in largest amount in sea salt are chlorine, bromine, sulphur, potassium, sodium, calcium and magnesium.
Sorensen and Martin Knudsen after a careful investigation decided to abandon the old definition of salinity as the sum of all the dissolved solids in sea-water and to substitute for it the weight of the dissolved solids in 1000 parts by weight of sea-water on the assumption that all the bromine is replaced by its equivalent of chlorine, all the carbonate converted into oxide and the organic matter burnt.
The advantage of the new definition lies in the fact that the estimation of the chlorine (or rather of the total halogen expressed as chlorine) is sufficient to determine the salinity by a very simple operation.
Such a simple formula is only possible because the salts of sea-water are of such uniform composition throughout the whole ocean that the chlorine bears a constant ratio to the total salinity as newly defined whatever the degree of concentration.
Sorensen, carried out a careful investigation of the relation between the amount of chlorine, the total salinity and the specific gravity of sea-water of different strengths including an entirely new determination of the thermal expansion of sea-water.
The relations between the various conditions are set forth in the following equations where 0-o signifies the specific gravity of the sea-water in question at o° C., the standard at 4° being taken as 1000, S the salinity and Cl the chlorine, both expressed in parts by weight per mille.
Such, for instance, were those of Spindler and Wrangell in the Black Sea by sinking an electric lamp, those of Paul Regnard by measuring the change of electric resistance in a selenium cell or the chemical action of the light on a mixture of chlorine and hydrogen, by which he found a very rapid diminution in the intensity of light even in the surface layers of water.
The formulae show the number of cubic centimetres of gas absorbed by i litre of sea-water; t indicates the temperature in degrees centigrade and CI the salinity as shown by the amount of chlorine per mille: 02 = 10.291 - 0 .
CsCl, is obtained by the direct action of chlorine on caesium, or by solution of the hydroxide in hydrochloric acid.
Acetylene has the property of inflaming spontaneously when brought in contact with chlorine.
If a few pieces of carbide be dropped into saturated chlorine water the bubbles of gas take I.
a, l by the action of water upon calcium carbide, prepared}' p fire as they reach the surface, and if a jet of acetylene be passed up into a bottle of chlorine it takes fire and burns with a heavy red flame, depositing its carbon in the form of soot.
If chlorine be bubbled up into a jar of acetylene standing over water, a violent explosion, attended with a flash of intense light and the deposition of carbon, at once takes place.
This second method of production has the great drawback that, unless proper precautions are taken to purify the gas obtained from the copper acetylide, it is always contaminated with certain chlorine derivatives of acetylene.
It is infusible at temperatures up to 2000° C., but can be fused in the electric arc. When heated to temperature of 2 4 5° C. in a stream of chlorine gas it becomes incandescent, forming calcium chloride and liberating carbon, and it can also be made to burn in oxygen at a dull red heat, leaving behind a residue of calcium carbonate.
Oxidation gives formaldehyde, formic acid and carbonic acid; chlorine and bromine react, but less readily than with ethyl alcohol.
Chemical methods of sterilization have also been suggested, depending on the use of iodine, chlorine, bromine, ozone, potassium permanganate, copper sulphate or chloride and ()their substances.
The sulphide is converted into sodium osmichloride by fusion with salt, in a current of chlorine, the sodium salt transformed into ammonium salt by precipitation with ammonium chloride, and the ammonium salt finally heated strongly (H.
It combines with fluorine at loo° C., and when heated with chlorine it forms a mixture of chlorides.
Osmium dichloride, OsC1 21 is obtained as a dark coloured powder when the metal is heated in a current of chlorine.
The tetrachloride, OsC1 41 is obtained as a dark red sublimate (mixed with the dichloride) when osmium is l}eated in dry chlorine.
Potassium osmichloride, K 2 OsC1 6, is formed when a mixture of osmium and potassium chloride is heated in a current of chlorine, or on adding potassium chloride and alcohol to a solution of the tetroxide in hydrochloric acid.
Zirconium chloride, ZrC1 4, is prepared as a white sublimate by igniting a mixture of zirconia and charcoal in a current of chlorine.
Other constituents are cholesterol (0.461.32%), traces of calcium, magnesium, sodium, chlorine and bromine, and various aliphatic amines which are really secondary products, being formed by the decomposition of the cellular tissue.
Heated in chlorine or with bromine, it yields carbon and calcium chloride or bromide; at a dull red heat it burns in oxygen, forming calcium carbonate, and it becomes incandescent in sulphur vapour at 500°, forming calcium sulphide and carbon disulphide.
Chlorine takes fire when passed into ammonia, nitrogen and hydrochloric acid being formed, and unless the ammonia be present in excess, the highly explosive nitrogen chloride NC1 3 is also produced.
It crystallizes in small needles, which are readily soluble in water, and on heating, decompose at about 102° C., with liberation of nitrogen, chlorine and oxygen.
Moissan); it has been liquefied, the liquid also being of a yellow colour and boiling at - 187° C. It is the most active of all the chemical elements; in contact with hydrogen combination takes place between the two gases with explosive violence, even in the dark, and at as low a temperature as - 210 C.; finely divided carbon burns in the gas, forming carbon tetrafluoride; water is decomposed even at ordinary temperatures, with the formation of hydrofluoric acid and "ozonised" oxygen; iodine, sulphur and phosphorus melt and then inflame in the gas; it liberates chlorine from chlorides, and combines with most metals instantaneously to form fluorides; it does not, however, combine with oxygen.
For the processes of the paper manufacturer esparto is used in the dry state, and without cutting; roots and flowers and stray weeds are first removed, and the material is then boiled with caustic soda, washed, and bleached with chlorine solution.
Among the difficulties here to be contended with are the destructive action of fused chlorides and of the reduced alkali metals upon most non-metallic substances available for the containing vessel and its partition, and also of the anode chlorine upon metals; also the low fusing-point (95° C. for sodium, and 62° C. for potassium) and the low specific gravity of the metals, so that the separated metal floats as a fused layer upon the top of the melted salt.
Sodium hydroxide has certain advantages compared with chloride, although it is more costly; its fusing-point is only 320° C., and no anode chlorine is produced, so that both containing vessel and anode may be of iron, and no porous partition is necessary.
As unsaturated compounds they can combine with two monovalent atoms. Hydrogen is absorbed readily at ordinary temperature in the presence of platinum black, and paraffins are formed; the halogens (chlorine and bromine) combine directly with them, giving dihalogen substituted compounds; the halogen halides to form monohalogen derivatives (hydriodic acid reacts most readily, hydrochloric acid, least); and it is to be noted that the haloid acids attach themselves in such a manner that the halogen atom unites itself to the carbon atom which is in combination with the fewest hydrogen atoms (W.
It is purified by boiling with acids, to remove any mineral matter, and is then ignited for a long time in a current of chlorine in order to remove the last traces of hydrogen.
It may be prepared by the direct union of carbon monoxide and chlorine in sunlight (Th.
Chemie, 1867, 3, p. 39), ascribes to the molecule a peroxide configuration which accounts for its oxidizing powers but not for the fact that each oxygen atom is capable of replacement by one atom of chlorine.
For the oxyhalogen salts see Chlorate, Chlorine, Bromine and Iodine.
The analysis of manganese dioxide in 1774 led him to the discovery of chlorine and baryta; to the description of various salts of manganese itself, including the manganates and permanganates, and to the explanation of its action in colouring and decolourizing glass.
Iodine may also be prepared by the decomposition of an iodide with chlorine, or by heating a mixture of an iodide and manganese dioxide with concentrated sulphuric acid.
Commercial iodine may be purified by mixing it with a little potassium iodide and then subliming the mixture; in this way any traces of bromine or chlorine are removed.
Iodine possesses a characteristic penetrating smell, not so pungent, however, as that of chlorine or bromine.
Its chemical properties closely resemble those of chlorine and bromine; its affinity for other elements, however, is as a rule less than that of either.
Iodine finds application in organic chemistry, forming addition products with unsaturated compounds, the combination, however, being more slow than in the case of chlorine or bromine.
Nitrous acid and chlorine readily decompose them with liberation of iodine; the same effect being produced when they are heated with concentrated sulphuric acid and manganese dioxide.
Iodine combines with chlorine to form iodine monochloride, IC1, which may be obtained by passing dry chlorine over dry iodine until the iodine is completely liquefied, or according to R.
The trichloride, IC1 31 results from the action of excess of chlorine on iodine, or from iodic acid and hydrochloric acid, or by heating iodine pentoxide with phosphorus pentachloride.
It crystallizes in long yellow needles and decomposes readily on heating into the monochloride and chlorine.
The peculiar nature of the action between iodine and chlorine in aqueous solution has led to the suggestion that the product is a base, i.e.
Iodic Acid, H10 3, can be prepared by dissolving iodine pentoxide in water; by boiling iodine with fuming nitric acid, 61+10HN03= 6H10 3 +10N0+2H 2 O; by decomposing barium iodate with the calculated quantity of sulphuric acid, previously diluted with water, or by suspending iodine in water and passing in chlorine, 12+5C12+ 6H 2 0=2H10 3 +10HC1.
It is a most powerful oxidizing agent, phosphorus being readily oxidized to phosphoric acid, arsenic to arsenic acid, silicon at 250° C. to silica, and hydrochloric acid to chlorine and water.
They are more easily reduced than the corresponding chlorates; an aqueous solution of hydriodic acid giving free iodine and a metallic oxide, whilst aqueous hydrochloric acid gives iodine trichloride, chlorine, water and a chloride.
Potassium ferricyanide, K 3 Fe(NC)s, red prussiate of potash, is obtained by oxidizing potassium ferrocyanide with chlorine, bromine, &c., 2K 4 Fe(NC) 6 + C1 2 = 2K 3 Fe(NC) 6 + 2KC1.
Heated with concentrated hydrochloric acid it liberates chlorine, and with sulphuric acid it liberates oxygen.
Chromic chloride, CrC1 31 is obtained in the anhydrous form by igniting a mixture of the sesquioxide and carbon in a current of dry chlorine; it forms violet laminae almost insoluble in water, but dissolves rapidly in presence of a trace of chromous chloride; this action has been regarded as a catalytic action, it being assumed that the insoluble chromic chloride is first reduced by the chromous chloride to the chromous condition and the original chromous chloride converted into soluble chromic chloride, the newly formed chromous chloride then reacting with the insoluble chromic chloride.
The violet form gives a purple solution, and all its chlorine is precipitated by silver nitrate, the aqueous solution containing four ions, probably Cr(OH 2) 6 and three chlorine ions.
The green salt appears to dissociate in aqueous solution into two ions, namely CrC1 2 (OH 2) 4 and one chlorine ion, since practically only one-third of the chlorine is precipitated by silver nitrate solution at o° C. Two of the six water molecules are easily removed in a desiccator, and the salt formed, CrC13.4H20, resembles the original salt in properties, only one-third of the chlorine being precipitated by silver nitrate.
It dissolves iodine and absorbs chlorine, and is decomposed by water with formation of chromic and hydrochloric acids; it takes fire in contact with sulphur, ammonia, alcohol, &c., and explodes in contact with phosphorus; it also acts as a powerful oxidizing agent.
Heated in a closed tube at 180° C. it loses chlorine and leaves a black residue of trichromyl chloride, Cr 3 0 6 C1 2, which deliquesces on exposure to air.
When there is appreciable absorption as in the case of the vapours of chlorine, bromine, iodine, sulphur, selenium and arsenic, luminosity begins at a red heat.
There is a vast amount of literature on the subject, but in spite of the difficulty of conceiving a luminous carbon vapour at the temperature of an ordinary carbon flame, the evidence seems to show that no other element is necessary for its production as it is found in the spectrum of pure carbon tetrachloride and certainly in cases where chlorine is excluded.
the flames of chlorine in hydrogen) do not apparently emit the usual sodium radiation when a sodium salt is placed in them.
The detection of the presence of chlorine or bromine or iodine in a compound is at present undecided, and it may be well that we may have to look for its effects in a different part of the spectrum.
Borchers also used an externally heated metal vessel as the cathode; it is provided with a supporting collar or flange a little below the top, so that the upper part of the vessel is exposed to the cooling influence of the air, in order that a crust of solidified salt may there be formed, and so prevent the creeping of the electrolyte over the top. The carbon anode passes through the cover of a porcelain cylinder, open at the bottom, and provided with a side-tube at the top to remove the chlorine formed during electrolysis.
When magnesium is heated in fluorine or chlorine or in the vapour of bromine or iodine there is a violent reaction, and the corresponding halide compounds are formed.
Magnesium oxychloride when heated to redness in a current of air evolves a mixture of hydrochloric acid and chlorine and leaves a residue of magnesia, a reaction which is employed in the Weldon-Pechiney and Mond processes for the manufacture of chlorine.
He made a special study of chlorine, and discovered two new chlorides of carbon.
In order to explain the electrical properties of a solution, for instance of potassium chloride, we are driven to believe that each molecule of the salt is dissociated into two parts, potassium and chlorine, each associated with an electric charge equal in amount but opposite in sign.
Thus he distrusted, and probably never fully accepted, Gay-Lussac's conclusions as to the combining volumes of gases; he held peculiar and quite unfounded views about chlorine, even after its elementary character had been settled by Davy; he persisted in using the atomic weights he himself had adopted, even when they had been superseded by the more accurate determinations of other chemists; and he always objected to the chemical notation devised by J.
To obtain the anhydrous single or double chloride, alumina must be ignited with carbon in a current of chlorine, and to exclude iron from the finished metal, either the alumina must be pure or the chloride be submitted to purification.
This preparation of a chlorine compound suited for electrolysis becomes more costly and more troublesome than that of the oxide, and in addition four times as much raw material must be handled.
This purified oxide, mixed with sodium chloride and coal tar, was carbonized at a red heat, and ignited in a current of dry chlorine as long as vapours of the double chloride were given off, these being condensed in suitable chambers.
Weldon's method of regenerating the spent chlorine liquors.
It is not magnetic. It stands near the positive end of the list of elements arranged in electromotive series, being exceeded only by the alkalis and metals of the alkaline earths; it therefore combines eagerly, under suitable conditions, with oxygen and chlorine.
Aluminium chloride, AlC1 3, was first prepared by Oersted, who heated a mixture of carbon and alumina in a current of chlorine, a method subsequently improved by Wohler, Bunsen, Deville and others.
A purer product is obtained by heating aluminium turnings in a current of dry chlorine, when the chloride distils over.
Sodium amalgam reduces them to secondary alcohols; phosphorus pentachloride replaces the carbonyl oxygen by chlorine, forming the ketone chlorides.
It readily forms addition products with chlorine and with hydrogen; the dichloride, C10H8C12, is obtained as a yellow liquid by acting with hydrochloric acid and potassium chlorate; the solid tetrachloride, C,o 11 8 C1 4, results when chlorine is passed into naphthalene dissolved in chloroform.
For what reason this volume may differ from case to case lies close at hand; in connexion with the notion of negative and positive atoms, like chlorine and hydrogen, experience tends to show that the former, as well as the latter, have a mutual repulsive power, but the former acts on the latter in the opposite sense; the necessary consequence is that, when those negative and positive groups are distributed in the molecule, its volume will be smaller than if the negative elements are heaped together.
Now taking the isomers H 3 C CC1 3 (M„ = 108) and C1H 2 C CHC1 2 (M„ = we see the negative chlorine atoms heaped up in the left hand formula, but distributed in the second; the former therefore may be presumed to occupy a larger space, the molecular volume, that is, the volume in cubic centimetres occupied by the molecular weight in grams, actually being 108 in the former, and 103 in the latter case (compare Chemistry: Physical).
It burns in air, and also in chlorine and bromine, and is readily oxidized by nitric acid.
rend., 1905, 40, p. 1181), by the action of chlorine or hydrochloric acid on the residue obtained by evaporating the oxide with hydrochloric acid.
It combines readily with fluorine, chlorine and bromine, and also with sulphur, selenium, phosphorus, &c.
Beryllium chloride BeC1 2, like aluminium chloride, may be prepared by heating a mixture of the oxide and sugar charcoal in a current of dry chlorine.
In his researches on the bleaching compounds of chlorine he was the first to advance the view that bleaching-powder is a double compound of calcium chloride and hypochlorite; and he devoted much time to the problem of economically obtaining soda and potash from seawater, though here his efforts were nullified by the discovery of the much richer sources of supply afforded by the Stassfurt deposits.
HYDROCHLORIC ACID, also known in commerce as "spirits of salts" and "muriatic acid," a compound of hydrogen and chlorine.
Its chemistry is discussed under Chlorine, and its manufacture under Alkali Manufacture.
It is also formed when the metal is burnt in chlorine.
Hydrochloric acid gives thallous chloride and chlorine; sulphuric acid gives off oxygen; and on heating it first gives the trioxide and afterwards the monoxide.
Thallic chloride, T1C1 3, is obtained by treating the monochloride with chlorine under water; evaporation in a vacuum gives colourless deliquescent crystals of T1C1,.H20.
By heating the metal or thallous chloride in chlorine, T1C1 T1C1 3 is obtained, which on further heating gives3TlCI.T1C13.
The chlorine is not completely precipitated by silver nitrate in nitric acid solution, the ionization apparently not proceeding to all the chlorine atoms. Thallic iodide, T11 3, is interesting on account of its isomorphism with rubidium and caesium tri-iodides, a resemblance which suggests the formula T11 (12) for the salt, in which the metal is obviously monovalent.
Dry chlorine gas passed into melted urea decomposes it with formation of cyanuric acid and ammonium chloride, nitrogen and ammonia being simultaneously liberated.
Biuret (allophanamide), NH 2 CO NH CO NH 2, is formed by heating urea; by the action of ammonia on allophanic ester; and by heating urea to 140° C. and passing chlorine into the melt at 140-150° C. (J.
Benzoyl chloride, C 6 H S 0001, is formed by distilling a mixture of phosphorus pentachloride and benzoic acid; by the action of chlorine on benzaldehyde, or by passing a stream of hydrochloric acid gas over a mixture of benzoic acid and phosphorus pentoxide heated to 200°C. (C. Friedel, Ben.
157171); by passing chlorine into milk of lime (C. Winkler, Jour.
It is a reddish-brown powder, which when heated with hydrochloric acid yields chlorine.
When heated with concentrated hydrochloric acid it yields chlorine, and with concentrated sulphuric acid it yields oxygen.
Such mixtures are obtained by the action of alkaline hypochlorites on manganous salts, or by suspending manganous carbonate in water and passing chlorine through the mixture.
The manganites are amorphous brown solids, insoluble in water, and decomposed by hydrochloric acid with the evolution of chlorine.
The potassium salt, KMnO 4, may be prepared by passing chlorine or carbon dioxide through an aqueous solution of potassium manganate, or by the electrolytic oxidation of the manganate at the anode [German patent 101710 (1898)].
It decomposes when heated to 200° - 240°C.: 2KMn04=K2Mn04+Mn02+02; and when warmed with hydrochloric acid it yields chlorine: 2 KM nO 4 + 16HC1= 2KC1 +2 MnC1 2 +8H 2 0 +5C12.
The valuation of pyrolusite is generally carried out by means of a distillation with hydrochloric acid, the liberated chlorine passing through a solution of potassium iodide, and the amount of iodine liberated being ascertained by means of a standard solution of sodium thiosulphate.
It is permanent in dry air, but tarnishes in moist air; it can be hammered and rolled; it melts at 623° C. It burns readily on heating, with a brilliant flame; and it also combines with chlorine,bromine, iodine, sulphur, phosphorus and cyanogen.
By suspending the precipitated cerous hydroxide in water and passing chlorine through the solution, a hydrated form of the dioxide, 2CeO 2.3H 2 O, is obtained, which is readily soluble in nitric and sulphuric acids, forming ceric salts, and in hydrochloric acid, where it forms cerous chloride, with liberation of chlorine.
Cerous chloride, CeC1 3, is obtained when the metal is burned in chlorine; when a mixture of cerous oxide and carbon is heated in chlorine; or by rapid heating of the dioxide in a stream of carbon monoxide and chlorine.
We also treat of the utilization of hydrochloric acid for the manufacture of chlorine and its derivatives, which are usually comprised within the meaning of the term " alkali manufacture."
Preparation of chlorine.
Employment of chlorine for the manufacture of bleachingpowder and of chlorates.
The gaseous hydrochloric acid evolved during all this time must be absorbed in water, unless it is directly converted into chlorine (see below, 2 and 3).
(Sectional as there is a sale for hydrochloric acid, or a consumption of the latter for the manufacture of chlorine.
Preparation of Chlorine.
- In this place we speak only of the preparation of chlorine from hydrochloric acid by chemical processes; the electrolytic processes will be treated hereafter.
It is clear that free chlorine must be prepared from hydrochloric acid by oxidizing the hydrogen.
Even now, where chlorine is required for immediate use in some other chemical operations on a comparatively small scale, it is obtained by the action of hydrochloric acid on native manganese dioxide, according to the equation: Mn02+4HC1= MnC1 2 +C1 2 +2H 2 0.
Owing to the impossibility of employing any metal in contact with the acid, the " chlorine stills," where the above reaction is carried out, must be made of acid-proof stones or " chemical " stoneware.
Moreover it is of a most disagreeable kind, as the waste "still-liquor," containing very much free hydrochloric acid and even some free chlorine, forms a most deleterious impurity when finding its way into drains or watercourses, apart from the intolerable nuisance caused by the escapes of chlorine from the stills and otherwise, which cannot be at all times avoided.
The difficulty was only overcome by the Weldon process, being the inventions of Walter Weldon from 1866 onwards, and his process up to this day furnishes the greater proportion of chlorine manufactured in the world.
There are also other advantages of this process which explain its wide extension, in spite of the fact that only from 30 to 35 parts of the hydrochloric acid employed is converted into chlorine, the remainder ultimately leaving the factory in the shape of a harmless but useless solution of calcium chloride.
Weldon's later attempts at superseding his classical process by other inventions which utilize a larger proportion of the chlorine, introduced as hydrochloric acid, have not been successful in the long run, although some of them were aided by the great technical skill of A.
Weldon Chlorine Still.
(Sectional Elevation.) Scale C, Stone steam column resting in stone socket process, by employing the active oxygen of manganese dioxide to convert hydrochloric acid into free chlorine, and he employed the atmospheric oxygen only indirectly, for the recovery of manganese dioxide from the manganese chloride formed.
5), to a larger extent into chlorine and water, of course mixed with the excess of oxygen and all the nitrogen of the air.
Where (as is the more usual case) the chlorine has to serve for the manufacture of bleaching-powder, it must first be deprived of the great amount of moisture which it contains, by means of coke-towers fed with moderately strong sulphuric acid.
The Deacon process makes cheaper chlorine than the Weldon process, but the plant is complicated and costly and the working requires a great deal of attention.
Applications of Chlorine.
- Some of the chlorine manufactured (practically only such as is obtained by the electrolysis of chlorides) is con densed by cold and pressure into liquid chlorine.
Sometimes the chlorine is employed directly for bleaching purposes, especially for some kinds of paper.
But most of the chlorine is utilized for the production of bleaching-powder, of bleach-liquor, and of chlorate of potash.
Bleaching-powder is a compound obtained by the action of free chlorine on hydrated lime, containing a slight excess of water at ordinary temperatures or slightly above these.
Chlorine, generated in an ordinary or a Weldon still, is passed in and is rapidly absorbed.
absorption becomes slow, the gas is cut off and the chamber is left to itself for twelve hours or more, when it will be found that all the chlorine has been taken up. Now the door of the chamber is opened, the powder lying at the bottom is turned over and the treatment with gas is repeated.
35% of " available " chlorine.
The weak chlorine from the Deacon process cannot be treated in this manner, as chambers of impossibly large dimensions would be required.
Originally the absorption of the Deacon chlorine took place in a set of chambers, constructed of large slabs of stone, containing a great many horizontal shelves superposed over one another.
About sixteen such chambers were combined in such manner that the fresh gas passed into that chamber which had been the longest time at work and in which the bleaching-powder was nearly finished, and so forth until the gas, now all but entirely exhausted, reached the last-filled chamber in which it met with fresh lime and there gave up the last of the chlorine.
The weak chlorine gas from the Deacon apparatus travels precisely the opposite way, from the bottom upwards, the result being that finished bleachingpowder is continually discharged at the bottom and air free from chlorine leaves the apparatus at the top.
If the chlorine is made to act on cream of lime, care being taken that the temperature does not rise above 35° and that the chlorine is not in excess, a solution is obtained containing a mixture of calcium chloride and hypochlorite which is a very convenient agent for bleachers, but which does not bear the expense of carriage over long distances.
Similar liquids are obtained with a basis of sodium (" eau de Javel "), by passing chlorine into solutions of sodium carbonate.
- Formerly all chlorate of potash, as some is still, was obtained by passing chlorine into milk of lime, allowing the temperature to rise almost to the boiling-point, and continuing until the bleaching-solution, originally formed, is converted into a mixture of calcium chlorate and chloride, the final reaction being 6Ca(OH)2+6C12=5CaC12+Ca(C103)2+6H20.
All endeavours to obtain either hydrochloric acid or free chlorine in the ammoniasoda process have proved commercial failures, all the chlorine of the sodium chloride being ultimately lost in the shape of worthless calcium chloride.
The Leblanc process thus remained the sole purveyor of chlorine in its active forms, and in this way the fact is accounted for that, at least in Great Britain, the Leblanc process still furnishes nearly half of all the alkali made, though in other countries its proportional share is very much less.
The profit made upon the chlorine produced has to make up for the loss on the alkali.
It is true that all the chlorine combined with the sodium is lost partly as NaC1 and partly as CaC1 2; none of the innumerable attempts at recovering the chlorine from the waste liquor has been made to pay, and success is less likely than ever since the perfection of the electrolytic processes.
Electrolitic Alkali Manufacture In theory by far the simplest process for making alkalis together with free chlorine is the electrolysis of sodium (or potassium) chloride.
The chlorine escapes at the anode, the hydrogen at the cathode.
If the chlorine and the sodiun hydrate can act upon each other within the liquid, bleach-liquors are formed: 2NaOH+ C12= NaOC1+NaC1+H 2 0.
If, however, the action of the chlorine on the sodium hydrate is prevented, which can be done in various ways, they can both be collected in the isolated state and utilized as has been previously described, viz.
the chlorine can be used for the manufacture of liquid chlorine, bleaching-powder or other bleaching compounds, or chlorates, and the solution of sodium hydrate can be sold as such, or converted into solid caustic soda.
so that the chlorine can act upon the caustic soda or potash at a higher concentration and temperature, in which case chlorates are directly formed in the liquid: KC1+3H 2 0 = KC103+3H2.
In all these cases the chlorine, or the products made from it, really play a greater part than the alkali.
de Montlaur; a few years later the processes worked out at the Griesheim alkali works (near Frankfort) for the manufacture of caustic potash and chlorine established definitely the success of electrolysis in the field of potash, but even then none of the various processes working with sodium chloride had emerged from the experimental stage.
The intermediate layer of the salt solution, floating over the caustic soda solution, plays the part of a diaphragm, by preventing the chlorine evolved in the bell from acting on the sodium hydrate formed outside, and this solution offers much less resistance to the electric current than the ordinary diaphragms. This process therefore consumes less power than most others.
The same author wrote the articles on the manufacture of sodium and potassium compounds and on chlorine in Thorpe's Dictionary of Applied Chemistry (3 vols., 1890-1893).
With chlorine they yield substitution products.
Perceiving a molecular isonomy between them and the inorganic compounds of the metals from which they may be formed, he saw their true molecular type in the oxygen, sulphur or chlorine compounds of those metals, from which he held them to be derived by the substitution of an organic group for the oxygen, sulphur, &c. In this way they enabled him to overthrow the theory of conjugate compounds, and they further led him in 1852 to publish the conception that the atoms of each elementary substance have a definite saturation capacity, so that they can only combine with a certain limited number of the atoms of other elements.
Chlorine acts on it readily in the cold, bromine not so easily, and iodine only when the mixture is heated.
By heating gallium in a regulated stream of chlorine the dichloride GaC1 2 is obtained as a crystalline mass, which melts at 164° C. and readily decomposes on exposure to moist air.
The tichloride GaC1 3 is similarly formed when the metal is heated in a rapid stream of chlorine, and may be purified by distillation in an atmosphere of nitrogen.
With chlorine, in the presence of iodine or antimony chloride, it yields meta-chlornitrobenzene.
The second concerned the nature of "oxymuriatic acid" (chlorine).
Davy, passing through Paris on his way to Italy at the end of 1813, obtained a few fragments of iodine, which had been discovered by Bernard Courtois (1777-1838) in 1811, and after a brief examination by the aid of his limited portable laboratory perceived its analogy to chlorine and inferred it to be an element.
He too saw its resemblance to chlorine, and was obliged to agree with Davy's opinion as to its simple nature, though not without some hesitation, due doubtless to his previous declaration about chlorine.
His services to industry included his improvements in the processes for the manufacture of sulphuric acid (1818) and oxalic acid (1829); methods of estimating the amount of real alkali in potash and soda by the volume of standard acid required for neutralization, and for estimating the available chlorine in bleaching powder by a solution of arsenious acid; directions for the use of the centesimal alcoholometer published in 1824 and specially commended by the Institute; and the elaboration of a method of assaying silver by a standard solution of common salt, a volume on which was published in 1833.
Thorium chloride, ThC1 4, is obtained as white shining crystals by heating a mixture of carbon and thoria in a current of chlorine.
When heated with oxy-acids it dissolves, with evolution of oxygen, and with hydrochloric acid it evolves chlorine.
Nickel chloride, NiC1 2, is obtained in the anhydrous condition by heating the hydrated salt to 140° C., or by gently heating the finely divided metal in a current of chlorine.
It readily sublimes when heated in a current of chlorine, forming golden yellow scales.
Rubidium chloride, RbC1, is formed on burning rubidium in chlorine, or on dissolving the hydroxide in aqueous hydrochloric acid.
It combines with fluorine with incandescence at ordinary temperatures, and with chlorine at 250-300°; carbon, silicon, and boron, when heated with it in the electric furnace, give crystals harder than the ruby.
Its solution liberates chlorine from hydrochloric acid and iodine from potassium iodide.
The hexachloride, WC1 6, is obtained by heating the metal in a current of dry chlorine in the absence of oxygen or moisture, otherwise some oxychloride is formed; a sublimate of dark violet crystals appear at first, but as the hexachloride increases in quantity it collects as a very dark red liquid.
The dioxychloride, WO 2 C12, is obtained as a light lemon-yellow sublimate on passing chlorine over the brown oxide.
The term is applied to the four elements fluorine, chlorine, bromine and iodine, on account of the great similarity of their sodium salts to ordinary sea-salt.
Thus, as the atomic weight increases, the state of aggregation changes from that of a gas in the case of fluorine and chlorine, to that of a liquid (bromine) and finally to that of the solid (iodine); at the same time the melting and boiling points rise with increasing atomic weights.
The halogen of lower atomic weight can displace one of higher atomic weight from its hydrogen compound, or from the salt derived from such hydrogen compound, while, on the other hand, the halogen of higher atomic weight can displace that of lower atomic weight, from the halogen oxy-acids and their salts; thus iodine will liberate chlorine from potassium chlorate and also from perchloric acid.
On the other hand the stability of the known oxygen compounds increases with the atomic weight, thus iodine pentoxide is, at ordinary temperatures, a well-defined crystalline solid, which is only decomposed on heating strongly, whilst chlorine monoxide, chlorine peroxide, and chlorine heptoxide are very unstable, even at ordinary temperatures, decomposing at the slightest shock.
CHLORINE (symbol Cl, atomic weight 35.46 (0=16), a gaseous chemical element of the halogen group, taking its name from the colour, greenish-yellow (Gr.
Chlorine is never found in nature in the uncombined condition, but in combination with the alkali metals it occurs widely distributed in the form of rock-salt (sodium chloride); as sylvine and carnallite, at Stassfiirt; and to a smaller extent in various other minerals such as matlockite and horn-mercury.
The preparation of chlorine, both on the small scale and commercially, depends on the oxidation of hydrochloric acid; the usual oxidizing agent is manganese dioxide, which, when heated with concentrated hydrochloric acid, forms manganese chloride, water and chlorine: - Mn02-I-4HC1=MnC12+2H20+ C1 2.
Chlorine may also be obtained by the action of dilute sulphuric acid on bleaching powder.
Owing to the reduction in the supply of available hydrochloric acid (on account of the increasing use of the "ammonia-soda" process in place of the "Leblanc" process for the manufacture of soda) Weldon tried to adapt the former to the production of chlorine or hydrochloric acid.
The residual magnesium chloride of the ammonia-soda process is evaporated until it ceases to give off hydrochloric acid, and is then mixed with more magnesia; the magnesium oxychloride formed is broken into small pieces and heated in a current of air, when it gives up its chlorine, partly in the uncombined condition and partly in the form of hydrochloric acid, and leaves a residue of magnesia, which can again be utilized for the decomposition of more ammonium chloride (W.
Decomposition takes place and the issuing gas contains 18-20% of chlorine.
This percentage drops gradually, and when it is reduced to about 3% the temperature of the apparatus is lowered, by the admission of air, to about 350° C., and the air stream containing the small percentage of chlorine is led off to a second cylinder of pills, which have just been treated with ammonium chloride vapour and are ready for the hot air current.
More recently, owing to the production of caustic soda by electrolytic methods, much chlorine has consequently been produced in the same manner (see Alkali Manufacture).
Chlorine is a gas of a greenish-yellow colour, and possesses a characteristic unpleasant and suffocating smell.
Its critical temperature is 146° C. Liquid and solid chlorine are both yellow in colour.
At ordinary temperatures it unites directly with many other elements; thus with hydrogen, combination takes place in direct sunlight with explosive violence; arsenic, antimony, thin copper foil and phosphorus take fire in an atmosphere of chlorine, forming the corresponding chlorides.
Many compounds containing hydrogen are readily decomposed by the gas; for example, a piece of paper dipped in turpentine inflames in an atmosphere of chlorine, producing hydrochloric acid and a copious deposit of soot; a lighted taper burns in chlorine with a dull smoky flame.
The solution of chlorine in water, when freshly prepared, possesses a yellow colour, but on keeping becomes colourless, on account of its decomposition into hydrochloric acid and oxygen.
Water saturated with chlorine at 0° C. deposits crystals of a hydrate C1 2.8H 2 O, which is readily decomposed at a higher temperature into its constituents.
Chlorine hydrate has an historical importance, as by sealing it up in a bent tube, and heating the end containing the hydrate, whilst the other limb of the tube was enclosed in a freezing mixture, M.
Faraday was first able to obtain liquid chlorine.
Chlorine is used commercially for the extraction of gold and for the manufacture of "bleaching powder" and of chlorates.
In these latter cases the reaction may proceed in different directions; thus, with the aromatic hydrocarbons, chlorine in the cold or in the presence of a carrier substitutes in the benzene nucleus, but in the presence of sunlight or on warming, substitution takes place in the side chain.
Iodine, antimony trichloride, molybdenum pentachloride, ferric chloride, ferric oxide, antimony, tin, stannic oxide and ferrous sulphate have all been used as chlorine carriers.
The atomic weight of chlorine was determined by J.
- Chlorine combines with hydrogen to form hydrochloric acid, HC1, the only known compound of these two elements.
Davy in 1810 showed that it contained hydrogen and chlorine only, as up to that time it was considered to contain oxygen.
The commercial acid is usually yellow in colour and contains many impurities, such as traces of arsenic, sulphuric acid, chlorine, ferric chloride and sulphurous acid; but these do not interfere with its application to the preparation of bleaching powder, in which it is chiefly consumed.
The salts of hydrochloric acid, known as chlorides, can, in most cases, be prepared by dissolving either the metal, its hydroxide, oxide, or carbonate in the acid; or by heating the metal in a current of chlorine, or by precipitation.
Chlorine and oxygen do not combine directly, but compounds can be obtained indirectly.
Three oxides are known: chlorine monoxide, Cl 2 0, chlorine peroxide, C102, and chlorine heptoxide, C1207.
Chlorine monoxide results on passing chlorine over dry precipitated mercuric oxide.
Balard determined the volume composition of the gas by decomposition over mercury on gentle warming, followed by the absorption of the chlorine produced with potassium hydroxide, and then measured the residual oxygen.
Chlorine peroxide was first obtained by Sir H.
A mixture of chlorine peroxide and chlorine is obtained by the action of hydrochloric acid on potassium chlorate, and similarly, on warming a mixture of potassium chlorate and oxalic acid to 70° C. on the water bath, a mixture of chlorine peroxide and carbon dioxide is obtained.
Chlorine peroxide must be collected by displacement, as it is soluble in water and readily attacks mercury.
It is a very powerful oxidant; a mixture of potassium chlorate and sugar in about equal proportions spontaneously inflames when touched with a rod moistened with concentrated sulphuric acid, the chlorine peroxide liberated setting fire to the sugar, which goes on burning.
Chlorine heptoxide was obtained by A.
On the addition of iodine to this oxide, chlorine is liberated and a white substance is produced, which decomposes, on heating to 380° C., into iodine and oxygen; bromine is without action (see A.
Several oxy-acids of chlorine are known, namely, hypochlorous acid, HC10, chlorous acid, HC10 2 (in the form of its salts), chloric acid, HC10 3, and perchloric acid, HC10 4.
Hypochlorous acid is formed when chlorine monoxide dissolves in water, and can be prepared (in dilute solution) by passing chlorine through water containing precipitated mercuric oxide in suspension.
A solution of sodium hypochlorite (Eau de Javel), which can be prepared by passing chlorine into a cold aqueous solution of caustic soda, has been extensively used for bleaching purposes.
Chlorous acid is not known in the pure condition; but its sodium salt is prepared by the action of sodium peroxide on a solution of chlorine peroxide: 2C10 2 +Na 2 0 2 =2NaC10 2 +0 2.
The silver and lead salts are unstable, being decomposed with explosive violence at 100° C. On adding a caustic alkali solution to one of chlorine peroxide, a mixture of a chlorite and a chlorate is obtained.
Roscoe, pure perchlo: is acid distils over at first, but if the distillation be continued a white crystalline mass of hydrated perchloric acid, HC104 H20, passes over; this is due to the decomposition of some of the acid into water and lower oxides of chlorine, the water produced then combining with the pure acid to produce the hydrated form.
It may be distinguished from chloric acid by the fact that it does not give chlorine peroxide when treated with concentrated sulphuric acid, and that it is not reduced by sulphurous acid.
They may be prepared by dissolving or suspending a metallic oxide or hydroxide in water and saturating the solution with chlorine; by double decomposition; or by neutralizing a solution of chloric acid by a metallic oxide, hydroxide or carbonate.
They are all decomposed on heating, with evolution of oxygen; and in contact with concentrated sulphuric acid with liberation of chlorine peroxide.
Berthollet by the action of chlorine on caustic potash, and this method was at first used for its manufacture.
Sodium chlorate, NaC10 3, is prepared by the electrolytic process; by passing chlorine into milk of lime and decomposing the calcium chlorate formed by sodium sulphate; or by the action of chlorine on sodium carbonate at low temperature (not above 35° C.).
This conversion is effected by allowing the ferrous chloride liquors slowly to descend a tower, filled with pieces of wood, coke or quartz, where it meets an ascending current of chlorine.
It is also obtained by burning the metal in chlorine, by heating copper and cupric oxide with hydrochloric acid, or copper and cupric chloride with hydrochloric acid.
Cupric chloride, CuC1 2, is obtained by burning copper in an excess of chlorine, or by heating the hydrated chloride, obtained by dissolving the metal or cupric oxide in an excess of hydrochloric acid.
It can also be obtained by suspending barium carbonate in boiling water and passing in chlorine.
It decomposes steam at a red heat, and burns (especially when finely powdered) in chlorine.
Antimony trichloride ("Butter of Antimony"), SbCl 31 is obtained by burning the metal in chlorine; by distilling antimony with excess of mercuric chloride; and by fractional distillation of antimony tetroxide or trisulphide in hydrochloric acid solution.
These precipitated oxychlorides on continued boiling with water lose all their chlorine and ultimately give a residue of antimony trioxide.
Antimony pentachloride, SbC1 5, is prepared by heating the trichloride in a current of chlorine.
It is a nearly colourless fuming liquid of unpleasant smell, which can be solidified to a mass of crystals melting at-6° C. It dissociates into the trichloride and chlorine when heated.
Among the substances of which he investigated the composition were ammonia, sulphuretted hydrogen and prussic acid, and his experiments on chlorine, which he regarded, not as an element, but as oxygenated muriatic (oxymuriatic) acid, led him to propose it as a bleaching agent in 1785.
5 of a gramme of pure iron wire in a flask, in hydrochloric acid, oxidizing it with a little potassium chlorate, boiling off all traces of chlorine, deoxidizing by one of the methods described above, and titrating with the solution.
In a chloridizing roast chlorine produces its effect as nascent chlorine or gaseous hydrochloric acid.
As some watervapour is always present, hydrochloric acid will invariably be formed with the chlorine.
Abney and Baker have shown that the pure dry chloride does not blacken when exposed in a vacuous tube to light, and that the blackening is due to absorption of oxygen accompanied by a loss of chlorine.
Next year, in a paper read in July and in his fifth Bakerian lecture in November, he argued that oxymuriatic acid, contrary to his previous belief, was a simple body, and proposed for it the name "chlorine."
That substance, recently discovered in Paris, was attracting the attention of French chemists when he stepped in and, after a short examination with his portable chemical laboratory, detected its resemblance to chlorine and pronounced it an "undecompounded body."
In 1823, when Faraday liquefied chlorine, he read a paper which suggested the application of liquids formed by the condensation of gases as mechanical agents.
The nature of the substituent exerts a specific influence on the reaction; thus with chlorine or bromine, ortho-semidines and the diphenyl bases are the chief products; the dimethylamino, -N(CH 3) 2, and acetamino, -NHCOCH3, groups give the diphenyl base and the para-semidine respectively.
Selenium tetrachloride, SeCl 4, is obtained by passing excess of chlorine over selenium; by the action of phosphorus pentachloride on selenium dioxide: Se0 2 +PC1 5 =SeOC1 2 +POC1 3 i 3SeOC12-I-2POC13=3SeC14-1-P205; and by the action of thionyl chloride on selenium oxychoride.
It is a white solid which can be obtained crystalline by sublimation in a current of chlorine.
A more complex cyanide, Se3(CN)2, is obtained by passing a current of chlorine and air into an aqueous solution of potassium selenocyanide (A.
When a solution of chlorine is first added and then ammonia an emerald green colour, due to the formation of thalleoquin, is developed.
This test answers with a solution containing only 1 part of quinine in 5000, or in a solution containing not more than part if bromine be used instead of chlorine.
Guntz, Comptes rendus, 1896, 122, p. 2 44; 12 3, p. 1273) is a white solid which inflames when heated in chlorine.
Lithium chloride LiC1, prepared by heating the metal in chlorine, or by dissolving the oxide or carbonate in hydrochloric acid, is exceedingly deliquescent, melts below a red heat, and is very soluble in alcohol.
It is manufactured from the magnesium bromide contained in "bittern" (the mother liquor of the salt industry), by two processes, the continuous and the periodic. The continuous process depends upon the decomposition of the bromide by chlorine, which is generated in special stills.
A regular current of chlorine mixed with steam is led in at the bottom of a tall tower filled with broken bricks, and there meets a descending stream of hot bittern: bromine is liberated and is swept out of the tower together with some chlorine, by the current of steam, and then condensed in a worm.
Commercial bromine is rarely pure, the chief impurities present in it being chlorine, hydrobromic acid, and bromoform (M.
Gessner (Berichte, 1876, 9, p. 1507) removes chlorine by repeated shaking with water, followed by distillation over sulphuric acid; hydrobromic acid is removed by distillation with pure manganese dioxide, or mercuric oxide, and the product dried over sulphuric acid.
Its chemical properties are in general intermediate between those of chlorine and iodine; thus it requires the presence of a catalytic agent, or a fairly high temperature, to bring about its union with hydrogen.
They are decomposed by chlorine, with liberation of bromine and formation of metallic chlorides; concentrated sulphuric acid also decomposes them, with formation of a metallic sulphate and liberation of bromine and sulphur dioxide.
Hydrobromic acid and its salts can be readily detected by the addition of chlorine water to their aqueous solutions, when bromine is liberated; or by warming with concentrated sulphuric acid and manganese dioxide, the same result being obtained.
Bromic acid is obtained by the addition of the calculated amount of sulphuric acid (previously diluted with water) to the barium salt; by the action of bromine on the silver salt, in the presence of water, 5AgBrO, 3Br 2 3H 2 O = 5AgBr 6HBrO 3, or bypassing chlorine through asolution of bromine in water.
In a similar way the absorption of light in the coloured gas chlorine is found to be unaltered if the thickness is reduced by compression, because the density is increased in the same ratio that the thickness is reduced.
The tertiary phosphines are characterized by their readiness to pass into derivatives containing pentavalent phosphorus, and consequently they form addition compounds with sulphur, carbon bisulphide, chlorine, bromine, the halogen acids and the alkyl halides with great readiness.
Phosphorous acid, P(OH) 3, discovered by Davy in 1812, may be ' obtained by dissolving its anhydride, P 4 0 61 in cold water; by immersing sticks of phosphorus in a solution of copper sulphate contained in a well-closed flask, filtering from the copper sulphide and precipitating the sulphuric acid simultaneously formed by baryta water, and concentrating the solution in vacuo; or by passing chlorine into melted phosphorus covered with water, the first formed phosphorus trichloride being decomposed by the water into phosphorous and hydrochloric acids.
The solution is stable to oxidizing agents such as dilute hydrogen peroxide and chlorine, but is oxidized by potassium permanganate to phosphoric acid; it does not reduce salts of the heavy metals.
Phosphorus trifluorodichloride, PF3C12, prepared from chlorine and the trifluoride, is a pungentsmelling gas, which at 250° gives the pentachloride and fluoride.
Phosphorus trichloride or phosphorous chloride, PC13, discovered by Gay-Lussac and Thenard in 1808, is obtained by passing a slow current of chlorine over heated red phosphorus or through a solution of ordinary phosphorus in carbon disulphide (purifying in the latter case by fractional distillation).
With chlorine it gives the pentachloride, PC1 5, and with oxygen when heated phosphoryl chloride, POC1 3.
Phosphorus pentachloride, PC15, discovered by Davy in 1810 and analysed by Dulong in 1816, is formed from chlorine and the trichloride.
It sublimes when heated, but under pressure it melts at 148°, giving a normal vapour density, but on further heating it dissociates into the trichloride and chlorine; this dissociation may be retarded by vapourizing in an atmosphere of chlorine.
The absence of lines of the spectrum of any element from the solar spectrum is no proof that the element is absent from the sun; apart from the possibility that the high temperature and other circumstances may show it transformed into some unknown mode, which is perhaps the explanation of the absence of nitrogen, chlorine and other non-metals; if the element is of high atomic weight we should expect it to be found only in the lowest strata of the sun's atmosphere, where its temperature was nearly equal to that of the central globe, and so any absorption line which it showed would be weak.
Hydrochloric, hydrobromic, hydriodic, hydrofluoric, nitric, phosphoric and many other acids are manufactured by the action of sulphuric acid on their salts; the alkali and chlorine industries, and also the manufacture of bromine and iodine, employ immense quantities of this acid.
It is decomposed by chlorine in the presence of sunlight, with explosive violence.
Benzene hexachloride, C 6 H 6 C1 61 is formed by the action of chlorine on benzene in sunlight.
The tetramethyl derivative, amalic acid, C$(CH3)4N407, has been prepared by oxidizing caffeine with chlorine water, and forms colourless crystals which are only slightly soluble in hot water.
All the chlorine, however, does not appear to be removed by this process, the residue having the composition 82FeOH)3FeC13; but it may be by electrolysing in a porous cell (Tribot and Chretien, Compt.
Fremy investigated this discovery, made by Stahl in 1702, and showed that the same solution resulted when chlorine is passed into strong potash solution containing ferric hydrate in suspension.
It dissolves in acetic acid to form a red solution, is not decomposed by cold sulphuric acid, but with hydrochloric or nitric acid it yields barium and ferric salts, with evolution of chlorine or oxygen (Baschieri, Gazetta, 1906, 36, ii.
Ferrous chloride, FeC1 21 is obtained as shining scales by passing chlorine, or, better, hydrochloric acid gas, over red-hot iron, or by reducing ferric chloride in a current of hydrogen.
Ferric chloride, FeCl31 known in its aqueous solution to Glauber as oleum martis, may be obtained anhydrous by the action of dry chlorine on the metal at a moderate red-heat, or by passing hydrochloric acid gas over heated ferric oxide.
The solution is best prepared by dissolving the hydrate in hydrochloric acid and removing the excess of acid by evaporation, or by passing chlorine into the solution obtained by dissolving the metal in hydrochloric acid and removing the excess of chlorine by a current of carbon dioxide.
Vapour density determinations at 448° indicate a partial dissociation of the double molecule Fe2Cl6I on stronger heating it splits into ferrous chloride and chlorine.
It oxidizes on heating in air, and ignites in chlorine; on solution in mineral acids it yields ferrous and ammonium salts, hydrogen being liberated.
It deliquesces and oxidizes on exposure, inflames in dry chlorine and is reduced to ammonia by zinc dust.
Peroxides may be basic or acidic. Some basic oxides yield hydrogen peroxide with acids, others yield oxygen (these also liberate chlorine from hydrochloric acid), and may combine with lower acidic oxides to form salts of the normal basic oxide with the higher acidic oxide.
0: M n: 0,0: Pb: O, and giving oxygen with sulphuric acid, and chlorine with hydrochloric. L.
The important oxidizing agents include: oxygen, ozone, peroxides, the halogens chlorine and bromine, oxyacids such as nitric and those of chlorine, bromine and iodine, and also chromic and permanganic acid.
The trichloride, VC1 31 is a deliquescent solid formed when the tetrachloride is heated in a retort as long as chlorine is given off (Roscoe), or by heating vanadium trisulphide in a current of chlorine and fractionally distilling the resulting product at 150° C. in a current of carbon dioxide (Halberstadt, Ber., 1882, 15, p. 1619).
The tetrachloride, VC14, is formed by the direct union of vanadium and chlorine or by the action of sulphur chloride on vanadium pentoxide (Matignon, Comptes rendus, 1904, 138, p. 631).
It burns in an atmosphere of chlorine forming the trichloride; it also combines directly with bromine and sulphur on heating, while on fusion with alkalis it forms arsenites.
Chlorine, bromine and iodine decompose arsine readily, the action being most violent in the case of chlorine.
Arsenic trichloride, AsCl3, is prepared by distilling white arsenic with concentrated sulphuric acid and common salt, or by the direct union of arsenic with chlorine, or from the action of phosphorus pentachloride on white arsenic. It is a colourless oily heavy liquid of specific gravity 2.205 (o° C.), which, when pure and free from chlorine, solidifies at - 18°C., and boils at 132 °C. It is very poisonous and decomposes in moist air with evolution of white fumes.
Many organic arsenic compounds are known, analogous to those of nitrogen and phosphorus, but apparently the primary and secondary arsines, AsH2CH3 and AsH(CH3)2, do not exist, although the corresponding chlorine derivatives, AsCl2CH3, methyl arsine chloride, and AsCl(CH3)2, dimethyl arsine chloride, are known.
They do not possess basic properties; the halogen in the chlorine compounds is readily replaced by oxygen, and the oxides produced behave like basic oxides.
The chlorides AsCl2CH3 and AsCl(CH3)2 as well as As(CH3)3 are capable of combining with two atoms of chlorine, the arsenic atom apparently changing from the tri- to the penta-valent condition, and the corresponding oxygen compounds can also be oxidized to compounds containing one oxygen atom or two hydroxyl groups more, forming acids or oxides.
Many of his well-known researches were carried out in support of these views, one of the most important being that on the action of chlorine on acetic aci