Hydrochloric Sentence Examples

Iridium tetrachloride, IrC1 41 is obtained by dissolving the finely divided metal in aqua regia; by dissolving the hydroxide in hydrochloric acid; and by digesting the hydrated sesquichloride with nitric acid.

It is an indigo-blue powder, soluble in hydrochloric acid, but insoluble in dilute nitric and sulphuric acids.

It decomposes steam at a red heat, and slowly dissolves in dilute hydrochloric and sulphuric acids, but more readily in nitric acid.

The dithionates are all soluble in water and when boiled with hydrochloric acid decompose with evolution of sulphur dioxide and formation of a sulphate.

Concentrated hydrochloric acid converts it into oxamide.

To obtain pure sulphuretted hydrogen the method generally adopted consists in decomposing precipitated antimony sulphide with concentrated hydrochloric acid.

Podophyllin is a resinous powder obtained by precipitating an alcoholic tincture of the rhizome by means of water acidulated with hydrochloric acid.

Sodium amalgam or zinc and hydrochloric acid reduce it to lactic acid, whilst hydriodic acid gives propionic acid.

They form compounds with hydrochloric acid when this gas is passed into their ethereal solution; these compounds, however, are very unstable, being readily decomposed by water.

After the vigorous reaction has ceased and all the sodium has been used up, the mass is thrown into dilute hydrochloric acid, when the soluble sodium salts go into solution, and the insoluble boron remains as a brown powder, which may by filtered off and dried.

The dark product obtained is washed with water, hydrochloric acid and hydrofluoric acid, and finally calcined again with the oxide or with borax, being protected from air during the operation by a layer of charcoal.

Boron hydride has probably never been isolated in the pure condition; on heating boron trioxide with magnesium filings, a magnesium boride Mg 3 B 2 is obtained, and if this be decomposed with dilute hydrochloric acid a very evil-smelling gas, consisting of a mixture of hydrogen and boron hydride, is obtained.

After fusion, the melt is well washed with dilute hydrochloric acid and then with water, the nitride remaining as a white powder.

When heated with concentrated hydrochloric acid the amino group is replaced by the hydroxyl group and the phenolic eurhodols are produced.

A curious property is to be observed when a crystal of pharmacosiderite is placed in a solution of ammonia - in a few minutes the green colour changes throughout the whole crystal to red; on placing the red crystal in dilute hydrochloric acid the green colour is restored.

It can be purified by solution in hydrochloric acid and subsequent precipitation by metallic zinc.

Molybdenum sesquioxide, Mo 2 O 3, a black mass insoluble in acids, is formed by heating the corresponding hydroxide in vacuo, or by digesting the trioxide with zinc and hydrochloric acid.

It forms quadratic prisms, having a violet reflex and insoluble in boiling hydrochloric acid.

Several hydrated forms of the oxide are known, and a colloidal variety may be obtained by the dialysis of a strong hydrochloric acid solution of sodium molybdate.

The molybdates may be recognized by the fact that they give a white precipitate on the addition of hydrochloric or nitric acids to their solutions, and that with reducing agents (zinc and sulphuric acid) they give generally a blue coloration which turns to a green and finally to a brown colour.

It can also be obtained by passing sulphuretted hydrogen through a solution of the dioxide in hydrochloric acid.

The mixed solution of poiysulphides and thiosulphate of calcium thus produced is clarified, diluted largely, and then mixed with enough of pure dilute hydrochloric acid to produce a feebly alkaline mixture when sulphur is precipitated.

Water decomposes it violently with formation of hydrochloric and sulphurous acids.

Water decomposes it into hydrochloric and sulphurous acids.

In the Glatz process the lye is treated with a little milk of lime, the liquid then neutralized with hydrochloric acid, and the liquid filtered.

The mass is then covered with two-thirds of its weight of alcohol, and saturated with hydrochloric acid gas.

Thus by heating spirits of salt he obtained "marine acid air" (hydrochloric acid gas), and he was able to collect it because he happened to use mercury, instead of water, in his pneumatic trough.

Heating spirits of hartshorn, he was able to collect "alkaline air" (gaseous ammonia), again because he was using mercury in his pneumatic trough; then, trying what would happen if he passed electric sparks through the gas, he decomposed it into nitrogen and hydrogen, and "having a notion" that mixed with hydrochloric acid gas it would produce a "neutral air," perhaps much the same as common air, he synthesized sal ammoniac. Dephlogisticated air (oxygen) he prepared in August 1774 by heating red oxide of mercury with a burning-glass, and he found that in it a candle burnt with a remarkably vigorous flame and mice lived well.

Glycerin when treated with hydrochloric acid gives propenyl dichlorhydrin, which may be oxidized to s-dichloracetone.

Potassium cyanide reacts with this acid to form the corresponding dinitrile, which is converted by hydrochloric acid into citric acid.

Ruthenium in bulk resembles platinum in its general appearance, and has been obtained crystalline by heating an alloy of ruthenium and tin in a current of hydrochloric acid gas.

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.

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.

The distribution of weight in chemical change is readily expressed in the form of equations by the aid of these symbols; the equation 2HC1+Zn =ZnCl2+H2, for example, is to be read as meaning that from 73 parts of hydrochloric acid and 65 parts of zinc, 136 parts of zinc chloride and 2 parts of hydrogen are produced.

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.

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.

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.

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.

Among the Arabian and later alchemists we find attempts made to collate compounds by specific properties, and it is to these writers that we are mainly indebted for such terms as "alkali," " sal," &c. The mineral acids, hydrochloric, nitric and sulphuric acids, and also aqua regia (a mixture of hydrochloric and nitric acids) were discovered, and the vitriols, alum, saltpetre, sal-ammoniac, ammonium carbonate, silver nitrate (lunar caustic) became better known.

Glauber showed how to prepare hydrochloric acid, spiritus salis, by heating rock-salt with sulphuric acid, the method in common use to-day; and also nitric acid from saltpetre and arsenic trioxide.

The action of these acids on many metals was also studied; Glauber obtained zinc, stannic, arsenious and cuprous chlorides by dissolving the metals in hydrochloric acid, compounds hitherto obtained by heating the metals with corrosive sublimate, and consequently supposed to contain mercury.

A masterly device, initiated by him, was to collect gases over mercury instead of water; this enabled him to obtain gases previously only known in solution, such as ammonia, hydrochloric acid, silicon fluoride and sulphur dioxide.

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.

Davy also described and partially investigated the gas, named by him " euchlorine," obtained by heating potassium chlorate with hydrochloric acid; this gas has been more recently examined by Pebal.

A further generalization was effected by August Kekule, who rejected the hydrochloric acid type as unnecessary, and introduced the methane type and condensed mixed types.

For many years it had been known that a mixture of potassium chlorate and hydrochloric or sulphuric acids possessed strong.

Potassium chlorate and hydrochloric acid oxidize phenol, salicylic acid (o-oxybenzoic acid), and gallic acid ([2.3.4] trioxybenzoic acid) to tri chlorpyroracemic acid (isotrichlorglyceric acid), CC13 C(OH)2 C02H, a substance also obtained from trichloracetonitrile, CC1 3 CO CN, by hydrolysis.

If it possesses an alkaline or acid reaction, it must be tested in the first case for ammonia, and in the second case for a volatile acid, such as sulphuric, nitric, hydrochloric, &c.

Hold a small portion of the substance moistened with hydrochloric acid on a clean platinum wire in the fusion zone' of the Bunsen burner, and note any colour imparted to the flame.

Small portions should be successively tested with waterMilute hydrochloric acid, dilute nitric acid, strong hydrochloric acid, and a mixture of hydrochloric and nitric acids, first in the cold and then with warming.

For this purpose the cold solution is treated with hydrochloric acid, which precipitates lead, silver and mercurous salts as chlorides.

In this case, the precipitate is dissolved in as little as possible hydrochloric acid and boiled with ammonium acetate, acetic acid and ferric chloride.

The white precipitate formed by cold hydrochloric acid is boiled with water, and the solution filtered while hot.

The precipitate formed by sulphuretted hydrogen may contain the black mercuric, lead, and copper sulphides, dark-brown bismuth sulphide, yellow cadmium and arsenious sulphides, orange-red antimony sulphide, brown stannous sulphide, dull-yellow stannic sulphide, and whitish sulphur, the last resulting from the oxidation of sulphuretted hydrogen by ferric salts, chromates, &c. Warming with ammonium sulphide dissolves out the arsenic, antimony and tin salts, which are reprecipitated by the addition of hydrochloric acid to the ammonium sulphide solution.

Dissolve the residue in hydrochloric acid and test separately for antimony and tin.

The last two are dissolved out by cold, very dilute hydrochloric acid, and the residue is tested for nickel and cobalt.

The carbonates are dissolved in hydrochloric acid, and calcium sulphate solution is added to a portion of the solution.

If barium is present, the solution of the carbonates in hydrochloric acid is evaporated and digested with strong alcohol for some time; barium chloride, which is nearly insoluble in alcohol,is thus separated, the remainder being precipitated by a few drops of hydrofluosilicic acid, and may be confirmed by the ordinary tests.

Thus a normal solution of sodium carbonate contains 53 grammes per litre, of sodium hydrate 40 grammes, of hydrochloric acid 36.5 grammes, and so on.

Similarly, normal solutions of hydrochloric and nitric acids can be prepared.

In the second group, we may notice the application of litmus, methyl orange or phenolphthalein in alkalimetry, when the acid or alkaline character of the solution commands the colour which it exhibits; starch paste, which forms a blue compound with free iodine in iodometry; potassium chromate, which forms red silver chromate after all the hydrochloric acid is precipitated in solutions of chlorides; and in the estimation of ferric compounds by potassium bichromate, the indicator, potassium ferricyanide, is placed in drops on a porcelain plate, and the end of the reaction is shown by the absence of a blue coloration when a drop of the test solution is brought into contact with it.

The substance is heated with metallic sodium or potassium (in excess if sulphur be present) to redness, the residue treated with water, filtered, and ferrous sulphate, ferric chloride and hydrochloric acid added.

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.

Sulphur and phosphorus can sometimes be estimated by Messinger's method, in which the oxidation is effected by potassium permanganate and caustic alkali, or by potassium bichromate and hydrochloric acid.

Potassium bichromate and sulphuric acid oxidize it to carbon dioxide and water; and potassium chlorate and hydrochloric acid to chloranil.

In a purer condition it may be obtained by the action of sulphuric acid on a mixture of potassium nitrate and ferrous sulphate, or of hydrochloric acid on a mixture of potassium nitrate and ferric chloride.

Similar phenomena are seen in the case of a solution of hydrochloric acid.

The two solutions, then, will so act on each other when mixed that they become isohydric. Let us suppose that we have one very active acid like hydrochloric, in which dissociation is nearly complete, another like acetic, in which it is very small.

In order that the solutions of these should be isohydric and the concentrations of the hydrogen ions the same, we must have a very large quantity of the feebly dissociated acetic acid, and a very small quantity of the strongly dissociated hydrochloric, and in such proportions alone will equilibrium be possible.

Let us allow dilute sodium acetate to react with dilute hydrochloric acid.

In dilute solution such substances as hydrochloric acid and potash are almost completely dissociated, so that, instead of representing the reaction as HC1+KOH = KC1 d-H20, we must write The ions K and Cl suffer no change, but the hydrogen of the acid and the hydroxyl (OH) of the potash unite to form water, which is only very slightly dissociated.

The aldehyde group also reacts with phenyl hydrazine to form two phenylhydrazones; under certain conditions a hydroxyl group adjacent to the aldehyde group is oxidized and glucosazone is produced; this glucosazone is decomposed by hydrochloric acid into phenyl hydrazine and the keto-aldehyde glucosone.

The acid employed may be hydrochloric, which gives the best results, or sulphuric, which is used in Germany; sulphuric acid is more readily separated from the product than hydrochloric, since the addition of powdered chalk precipitates it as calcium sulphate, which may be removed by a filter press.

Treatment with a warm alkaline solution is afterwards advisable, in order to remove traces of hydrochloric acid generated during the process.

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.

With water it forms a hydrate, and ultimately decomposes into lead dioxide and hydrochloric acid.

This salt gives the corresponding chloride and fluoride with hydrochloric and hydrofluoric acids, and the phosphate, Pb(HP04)2, with phosphoric acid.

It is artificially obtained by adding hydrochloric acid to a solution of lead salt, as a white precipitate, little soluble in cold water, less so in dilute hydrochloric acid, more so in the strong acid, and readily soluble in hot water, from which on cooling, the excess of dissolved salt separates out in silky rhombic needles.

Powdered galena is dissolved in hot hydrochloric acid, the solution allowed to cool and the deposit of impure lead chloride washed with cold water to remove iron and copper.

Lead fluoride, PbF2, is a white powder obtained by precipitating a lead salt with a soluble fluoride; it is sparingly soluble in water but readily dissolves in hydrochloric and nitric acids.

It dissolves in strong nitric acid with the formation of the nitrate and sulphate, and also in hot concentrated hydrochloric acid.

Solutions of lead salts (colourless in the absence of coloured acids) are characterized by their behaviour to hydrochloric acid, sulphuric acid and potassium chromate.

But the most delicate precipitant for lead is sulphuretted hydrogen, which produces a black precipitate of lead sulphide, insoluble in cold dilute nitric acid, less so in cold hydrochloric, and easily decomposed by hot hydrochloric acid with formation of the characteristic chloride.

When heated with hydriodic acid and phosphorus it forms phenylacetic acid; whilst concentrated hydrobromic acid and hydrochloric acid at moderate temperatures convert it into phenylbromand phenylchlor-acetic acids.

By this means a mixture is obtained which by distillation or the action of hydrochloric acid yields trithioaldehyde, (C2H4S)3.

The residue is washed, extracted by dilute hydrochloric acid, and again well washed with boiling water.

It burns on heating in air; and is scarcely attacked by hydrochloric or nitric acids, or by aqua regia; it is soluble in warm concentrated sulphuric acid.

The oxyfluoride, CbOF 3, results when a mixture of the pentoxide and fluorspar is heated in a current of hydrochloric acid.

Dilute sulphuric acid attacks it but slowly; hydrochloric acid, especially if strong, dissolves it readily, with the formation, more immediately, of a hyacinthcoloured solution of U 2 C1 6, which, however, readily absorbs oxygen from the air, with the formation of a green solution of UC1 4, which in its turn gradually passes into one of yellow uranyl salt, U02.

It is also obtained by dissolving the oxide in hydrochloric acid and evaporating.

The iron plates, having been carefully cleaned with sand and hydrochloric or sulphuric acid, and lastly with water, are plunged into heated tallow to drive away the water without oxidation of the metal.

It is insoluble in water and in nitric acid and apparently so in hydrochloric acid; but if heated with this last for some time it passes into a compound, which, after the acid mother liquor has been decanted off, dissolves in water.

The solution when subjected to distillation behaves very much like a physical solution of the oxide in hydrochloric acid, while a solution of orthostannic acid in hydrochloric acid behaves like a solution of SnC1 4 in water, i.e.

A colloidal or soluble stannic acid is obtained by dialysing a mixture of tin tetrachloride and alkali, or of sodium stannate and hydrochloric acid.

A hydrated tin trioxide, Sn03, was obtained by Spring by adding barium dioxide to a solution of stannous chloride and hydrochloric acid; the solution is dialysed, and the colloidal solution is evaporated to form a white mass of 2Sn03 H20.

Stannous Chloride, SnC1 2, can only be obtained pure by heating pure tin in a current of pure dry hydrochloric acid gas.

This salt is also formed by dissolving tin in strong hydrochloric acid and allowing it to crystallize, and is industrially prepared by passing sufficiently hydrated hydrochloric acid gas over granulated tin contained in stoneware bottles and evaporating the concentrated solution produced in tin basins over granulated tin.

Stannic sulphide, SnS 2, is obtained by heating a mixture of tin (or, better, tin amalgam), sulphur and sal-ammoniac in proper proportions in the beautiful form of aurum musivum (mosaic gold) - a solid consisting of golden yellow, metallic lustrous scales, and used chiefly as a yellow "bronze" for plaster-of-Paris statuettes, &c. The yellow precipitate of stannic sulphide obtained by adding sulphuretted hydrogen to a stannic solution readily dissolves in solutions of the alkaline sulphides to form thiostannates of the formula M 2 SnS 31 the free acid, H2SnS3, may be obtained as an almost black powder by drying the yellow precipitate formed when hydrochloric acid is added to a solution of a thiostannate.

The solutions are oxidized, precipitated with ammonia, the precipitate dissolved in hydrochloric acid, and re-thrown down by boiling with sodium sulphate.

It burns when brought into contact with chlorine, forming silicon chloride and hydrochloric acid.

Smiles (Comptes rendus, 1902, pp. 5 6 9, 1 549) from the products obtained in the action of hydrochloric acid on magnesium silicide.

Water decomposes it into hydrochloric and silicic acids.

It decomposes water at ordinary temperature with evolution of hydrogen but without production of silicon hydride, whilst cold hydrochloric acid attacks it vigorously with evolution of hydrogen and spontaneously inflammable silicon hydride.

Aqueous Sulphuric or Hydrochloric Acid readily dissolves groups I and 2, with evolution of hydrogen and formation of chlorides or sulphates.

Aqua Regia, a mixture of nitric and hydrochloric acids, converts all metals (even gold, the "king of metals," whence the name) into chlorides, except only rhodium, iridium and ruthenium, which, when pure, are not attacked.

The chlorides AsC1 3, SbC1 3, BiC1 3, are at once decomposed by (liquid) water, with formation of oxide (As203) or oxychlorides (SbOC1, BiOCI) and hydrochloric acid.

All chlorides, except those of silver and mercury (and, of course, those of gold and platinum), are oxidized by steam at high temperatures, with elimination of hydrochloric acid.

On warming the osazone with hydrochloric acid the phenylhydrazine residues are removed and an osone results, which on reduction with zinc and acetic acid gives a ketose.

The osazone prepared from a-acrose resembled most closely the glucosazone yielded by glucose, mannose, and fructose, but it was optically inactive; also the ketose which it gave after treatment with hydrochloric acid and reduction of the osone was like ordinary fructose except that it was inactive.

We may notice that the pentoses differ from other sugars by yielding furfurol when boiled with hydrochloric acid.

By acting with hydrochloric acid on glucose Fischer obtained isomaltose, a disaccharose very similar to maltose but differing in being amorphous and unfermentable by yeast.

Styrolene is oxidized by nitric or chromic acids to benzoic acid; reduction gives ethylbenzene; hydrochloric and hydrobromic acids yield a-haloid ethylbenzenes, e.g.

In the ordinary chemical analyses of the soil determinations are made of the nitrogen and various carbonates present as well as of the amount of phosphoric acid, potash, soda, magnesia and other components soluble in strong hydrochloric acid.

The storing of such tobacco for a lengthened period matures and deprives it of harshness, and the same result may be artificially hastened by macerating the leaves in water acidulated with hydrochloric acid, and washing them out with pure water.

It combines directly with the halogens, and dissolves in cold dilute sulphuric acid, in hot strong hydrochloric acid and in aqua regia, but less readily in nitric acid.

A hydrated form is prepared when a solution of titanic acid in hydrochloric acid is digested with copper, or when the trichloride is precipitated with alkalis.

Wallach, Ber., 1881, 14, P. 421); by the action of reducing agents on nitroparaffins; by the action of zinc and hydrochloric acid on aldehyde ammonias (German Patent 73,812); by the reduction of the phenylhydrazones and oximes of aldehydes and ketones with sodium amalgam in the presence of alcohol and sodium acetate (J.

Hofmann), an alcoholic solution of stannous chloride (containing hydrochloric acid) (R.

Nitric, hydrochloric and sulphuric acids, all more or less impure, were better studied; and many ethereal oils were discovered.

Strontium chloride, SrC1 2.6H 2 O, is obtained by dissolving the carbonate in hydrochloric acid, or by fusing the carbonate with calcium chloride and extracting the melt with water.

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.

It is a white solid, which combines with gaseous ammonia to form SrC1 2.8NH 3, and when heated in superheated steam it decomposes with evolution of hydrochloric acid.

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.

Thus, a number of copper-tin alloys when digested with hydrochloric acid leave the same crystalline residue, which on analysis proves to be the compound Cu 3 Sn.

It is insoluble in hydrochloric, nitric and sulphuric acids, but dissolves in aqua regia - a mixture of hydrochloric and nitric acids - and when very finely divided in a heated mixture of strong sulphuric acid and a little nitric acid; dilution with water, however, precipitates the metal as a violet or brown powder from this solution.

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.

Aurous cyanide, AuCN, forms yellow, microscopic, hexagonal tables, insoluble in water, and is obtained by the addition of hydrochloric acid to a solution of potassium aurocyanide, KAu(CN)2.

The acid, auricyanic acid, 2HAu (CN) 4.3H20, is obtained by treating the silver salt (obtained by precipitating the potassium salt with silver nitrate) with hydrochloric acid; it forms tabular crystals, readily soluble in water, alcohol and ether.

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.

In the wet process the ores, in which the bismuth is present as oxide or carbonate, are dissolved out with hydrochloric acid, or, if the bismuth is to be extracted from a matte or alloy, the solvent employed is aqua regia or strong sulphuric acid.

Bismuth combines directly with the halogens, and the elements of the sulphur group. It readily dissolves in nitric acid, aqua regia, and hot sulphuric acid, but tardily in hot hydrochloric acid.

Bismuth disulphide is a grey metallic substance, which is decomposed by hydrochloric acid with the separation of metallic bismuth and the formation of bismuth trichloride.

The bottle is carefully cleansed by washing with soda, hydrochloric acid and distilled water, and then dried by heating in an air bath or by blowing in warm air.

The crude element is treated with aqua regia and then evaporated with an excess of hydrochloric acid, the solution diluted and the tellurium precipitated by a current of sulphur dioxide.

By heating with sodium amalgam and separating with hydrochloric acid, the dichloride, TaC1 2.2H 2 O, is obtained as emerald green hexagonal crystals.

CsCl, is obtained by the direct action of chlorine on caesium, or by solution of the hydroxide in hydrochloric acid.

This on being washed and decomposed with hydrochloric acid yielded a stream of acetylene gas.

The vessel, however, which contains this mixture has to be of earthenware, porcelain or enamelled iron on account of the free acid present; the gas must be washed after purification to remove traces of hydrochloric acid, and care must be taken to prevent the complete neutralization of the acid by the ammonia present in the gas.

Filtration in the chemical laboratory is commonly effected by the aid of a special kind of unsized paper, which in the more expensive varieties is practically pure cellulose, impurities like feric oxide, alumina, lime, magnesia and silica having been removed by treatment with hydrochloric and hydrofluoric acids.

By means of a piece of stretched rubber tubing, this crucible is supported in the mouth of an ordinary funnel which is connected with an exhausting apparatus; and water holding in suspension fine scrapings of asbestos, purified by boiling with strong hydrochloric acid and washing with water, is run through it, so that the perforated bottom is covered with a layer of felted asbestos.

Aposafranone, C,8H12N20, is formed by heating aposafranine with concentrated hydrochloric acid.

As an alternative the osmiridium is fused with zinc, the regulus treated with hydrochloric acid, and then heated with barium nitrate and barium peroxide.

After fusion, the mass is finely powdered and treated with cold dilute hydrochloric acid; and when action has finished, nitric and sulphuric acids are added, the precipitated barium sulphate removed, the liquid distilled and the osmium precipitated as sulphide.

The tetroxide, 0s04, can be easily reduced to the metal by dissolving it in hydrochloric acid and adding zinc, mercury, or an alkaline formate to the liquid, or by passing its vapour, mixed with carbon dioxide and monoxide, through a red-hot porcelain tube.

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.

Troost produced crystallized zirconium by fusing the double fluoride with aluminium in a graphite crucible at the temperature of melting iron, and extracting the aluminium from the melt with hydrochloric acid.

The precipitate, being difficult to wash, is (after a preliminary washing) re-dissolved in hydrochloric acid and re-precipitated with ammonia.

When heated with hydrochloric acid it gives isopilocarpine.

It is insoluble in water; slightly soluble in solutions of carbonic acid and common salt, and readily soluble in concentrated hydrochloric and nitric acid.

Of the acid orthophosphates, the mono-calcium salt, CaH4(P04)2, may be obtained as crystalline scales, containing one molecule of water, by evaporating a solution of the normal salt in hydrochloric or nitric acid.

Detection and Estimation.-Most calcium compounds, especially when moistened with hydrochloric acid, impart an orange-red colour to a Bunsen flame, which when viewed through green glass appears to be finch-green; this distinguishes it in the presence of strontium, whose crimson coloration is apt to mask the orange-red calcium flame (when viewed through green glass the strontium flame appears to be a very faint yellow).

Sulphuric acid gives a white precipitate of calcium sulphate with strong solutions; ammonium oxalate gives calcium oxalate, practically insoluble in water and dilute acetic acid, but readily soluble in nitric or hydrochloric acid.

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.

The amount of ammonia in ammonium salts can be estimated quantitatively by distillation of the salts with sodium or potassium hydroxide, the ammonia evolved being absorbed in a known volume of standard sulphuric acid and the excess of acid then determined volumetrically; or the ammonia may be absorbed in hydrochloric acid and the ammonium chloride so formed precipitated as ammonium chlorplatinate, (NH4)2PtC16.

Dr Thomson first pointed out a process by synthesis, which has the advantage of being very simple, and at the same time rigidly accurate, resulting from his observation that when hydrochloric acid gas and ammonia gas are brought in contact with each other, they always combine in equal volumes.

It is now obtained from the ammoniacal liquor of gas works by distilling the liquor with milk of lime and passing the ammonia so obtained into hydrochloric acid.

A variety of animal charcoal is sometimes prepared by calcining fresh blood with potassium carbonate in large cylinders, the mass being purified by boiling out with dilute hydrochloric acid and subsequent reheating.

It is rapidly absorbed by an ammoniacal or acid (hydrochloric acid) solution of cuprous chloride.

Water decomposes it violently, with formation of carbon dioxide and hydrochloric acid.

Hot concentrated nitric acid oxidizes it to picric acid and oxalic acid, whilst on treatment with hydrochloric acid and potassium chlorate it yields chloranil (tetrachloroquinone).

When hydrochloric acid gas is passed into the solution the salt is completely precipitated as a fine powder.

If the original solution contained the chlorides of magnesium or calcium or sulphate of potassium all impurities remain in the mother-liquor (the sulphur as KHS04), and can be removed by washing the precipitate with strong hydrochloric acid.

A later method consists in boiling the weed with sodium carbonate; the liquid is filtered and hydrochloric acid added to the filtrate, when alginic acid is precipitated; this is also filtered off, the filtrate neutralized by caustic soda, and the whole evaporated to dryness and carbonized, the residue obtained being known as kelp substitute.

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.

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.

He was an active worker in physiological chemistry, and carried out many analyses of the products of living organisms, among them being one of the gastric juice which, at the end of 1823, resulted in the notable discovery that the acid contents of the stomach contain hydrochloric acid which is separable by distillation.

The anhydrous acid combines with hydrochloric, hydrobromic and hydriodic acids to form crystalline addition products, which are decomposed by water with the formation of the corresponding ammonium salt and formic acid.

Hydroferrocyanic acid, H 4 Fe(NC)s, is best obtained by decomposing the lead salt with sulphuretted hydrogen under water, or by passing hydrochloric acid gas into a concentrated ether solution of the potassium salt.

It can be estimated quantitatively by mixing a dilute solution with potassium iodide and hydrochloric acid in excess, adding excess of zinc sulphate, neutralizing the excess of free acid with sodium bicarbonate, and determining the amount of free iodine by a standard solution of sodium thiosulphate.

Hydroferricyanic acid, H 3 Fe(NC)s, obtained by adding concentrated hydrochloric acid to a cold saturated solution of potassium ferricyanide, crystallizes in brown needles, and is easily decomposed.

The free acid forms dark red deliquescent crystals and is obtained by decomposing the silver salt with hydrochloric acid, or the barium salt with dilute sulphuric acid.

The metallic cyanides may be detected by adding ferrous sulphate, ferric chloride, and hydrochloric acid to their solution, when a precipitate of Prussian blue is produced; if the original solution contains free acid it must be neutralized by caustic potash before the reagents are added.

As an alternative test the cyanide may be decomposed by dilute hydrochloric acid, and the liberated hydrocyanic acid absorbed in a little yellow ammonium sulphide.

The esters of the acid may be obtained by distilling a mixture of the sodium or potassium salts and the corresponding alcohol with hydrochloric or sulphuric acids.

Wohler reduced the sesquioxide by zinc, and obtained a shining green powder of specific gravity 6.81, which tarnished in air and dissolved in hydrochloric acid and warm dilute sulphuric acid, but was unacted upon by concentrated nitric acid.

Chromium as prepared by the Goldschmidt process is in a passive condition as regards dilute sulphuric acid and dilute hydrochloric acid at ordinary temperatures; but by heating the metal with the acid it passes into the active condition, the same effect being produced by heating the inactive form with a solution.

Heated with concentrated hydrochloric acid it liberates chlorine, and with sulphuric acid it liberates oxygen.

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.

Potassium chlorochromate, CrO 2 Cl OK, is produced when potassium bichromate is heated with concentrated hydrochloric acid and a little water, or from chromium oxychloride and saturated potassium chloride solution, when - it separates as a red crystalline salt.

The constitution of methyl orange follows from the fact that on reduction by stannous chloride in hydrochloric acid solution it yields sulphanilic acid and para-aminodimethyl aniline.

Hydrochloric acid converts it into chloraniline, nitrogen being eliminated; whilst boiling sulphuric acid converts it into aminophenol.

Heated with anhydrous sodium acetate and acetic anhydride it gives cinnamic acid; with ethyl bromide and sodium it forms triphenyl-carbinol (C 6 H 5) 3 C OH; with dimethylaniline and anhydrous zinc chloride it forms leuco-malachite green C6H5CH[C6H4N(CH3)2]2; and with dimethylaniline and concentrated hydrochloric acid it gives dimethylaminobenzhydrol, C 6 H 5 CH(OH)C 6 H 4 N(CH 3) 2.

It may be prepared by dissolving the metal, its oxide, hydroxide, or carbonate in dilute hydrochloric acid, or by mixing concentrated solutions of magnesium sulphate and common salt, and cooling the mixture rapidly, when the less soluble sodium sulphate separates first.

The hydrated salt loses water on heating, and partially decomposes into hydrochloric acid and magnesium oxychlorides.

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.

It may also be obtained by the decomposition of boracite with hot hydrochloric acid.

Thus he clearly described the preparation of hydrochloric acid by the action of oil of vitriol on common salt, the manifold virtues of sodium sulphate - sal mirabile, Glauber's salt - formed in the process being one of the chief themes of his Miraculum mundi; and he noticed that nitric acid was formed when nitre was substituted for the common salt.

This result gives a value of D for dilute hydrochloric acid equal to 2.49 to compare with the observed value of 2.30.

Alumina dissolves readily enough in aqueous hydrochloric acid to yield a solution of the chloride, but neither this solution, nor that containing sodium chloride, can be evaporated to dryness without decomposition.

Potash-alum and pitch were calcined together, and the mass was treated with hydrochloric acid; charcoal and water to form a paste were next added, and the whole was dried and ignited in a current of air and steam.

To inorganic acids, except hydrochloric, it is highly resistant, ranking well with tin in this respect; but alkalis dissolve it quickly.

Crystallized alumina is also obtained by heating the fluoride with boron trioxide; by fusing aluminium phosphate with sodium sulphate; by heating alumina to a dull redness in hydrochloric acid gas under pressure; and by heating alumina with lead oxide to a bright red heat.

It is very hygroscopic, absorbing water with the evolution of hydrochloric acid.

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.

Hantzsch (Ber., 18 9 6, 2 9, p. 947 1898, 31, p. 1253) has shown that the chlorand bromdiazoniumthiocyanates, when dissolved in alcohol containing a trace of hydrochloric acid, become converted into the isomeric thiocyanbenzene diazonium chlorides and bromides.

Concentrated hydrochloric acid converts it into chlorbenzene, aniline and nitrogen.

Concentrated hydrochloric acid decomposes it with formation of C6H 6 N OH HO'N'H chloranilines and elimination of nitrogen, whilst on boiling with sulphuric acid it is converted into aminophenols.

Cavendish, who showed that it was formed when various metals were acted upon by dilute sulphuric or hydrochloric acids.

In preparing the gas by the action of metals on acids, dilute sulphuric or hydrochloric acid is taken, and the metals commonly used are zinc or iron.

To purify the oxide, it is dissolved in dilute hydrochloric acid until the acid is neatly neutralized, the solution is cooled, filtered, and baryta water is added until a faint permanent white precipitate of hydrated barium peroxide appears; the solution is now filtered, and a concentrated solution of baryta water is added to the filtrate, when a crystalline precipitate of hydrated barium peroxide, Ba0 2 8 H 2 0, is thrown down.

It may be recognized by the violet coloration it gives when added to a very dilute solution of potassium bichromate in the presence of hydrochloric acid; by the orange-red colour it gives with a solution of titanium dioxide in concentrated sulphuric acid; and by the precipitate of Prussian blue formed when it is added to a solution containing ferric chloride and potassium ferricyanide.

Meyer (Ber., 18 94, 2 7, p. 510 et seq.) showed that in benzenoid compounds ortho-substituents exert a great hindering effect on the esterification of alcohols by acids in the presence of hydrochloric acid, this hindering being particularly marked when two substituents are present in the ortho positions to the carboxyl group. In such a case the ester is best prepared by the action of an alkyl halide on the silver salt of the acid, and when once prepared, can only be hydrolysed with great difficulty.

Bernthsen); by the action of ammonium chloride or hydrochlorides of amines on nitriles; by condensing amines and amides in presence of phosphorus trichloride; by the action of hydrochloric acid on acid-amides (0.

By evaporation of a solution of lanthanum oxide in hydrochloric acid to the consistency of a syrup, and allowing the solution to stand, large colourless crystals of a hydrated chloride of the composition 2LaC1 3.15H 2 O are obtained.

In a fine state of division it takes fire on heating in air, but is permanent at ordinary temperatures in oxygen or air; it is readily attacked by hydrochloric and sulphuric acids, but scarcely acted on by nitric acid.

This process is repeated several times, and the final precipitate is dissolved in hydrochloric acid and precipitated by ammonia, washed and dried.

Hydrolysis with hydrochloric acid or baryta water gives tropic acid and tropine; on the other hand, by boiling equimolecular quantities of these substances with dilute hydrochloric acid, atropine is reformed.

From the filtered solution the thallium is precipitated as the chloride by addition of hydrochloric acid, along, in general, with more or less of lead chloride.

It is readily soluble in nitric and sulphuric acids, but less so in hydrochloric.

Thallous chloride, T1C1, is readily obtained from the solution of any thallous salt, by the addition of hydrochloric acid, as a white precipitate similar in appearance to silver chloride, like which it turns violet in the light and fuses below redness into a (yellow) liquid which freezes into a horn-like flexible mass.

Hydrochloric acid gives thallous chloride and chlorine; sulphuric acid gives off oxygen; and on heating it first gives the trioxide and afterwards the monoxide.

For this purpose the urine is concentrated and the hippuric acid precipitated by the addition of hydrochloric acid; it is then filtered and boiled for some time with concentrated hydrochloric acid, when it is hydrolysed into benzoic and amido-acetic acid.

It is made commercially by boiling benzotrichloride (obtained from toluene) with milk of lime, the calcium benzoate so obtained being then decomposed by hydrochloric acid 2C 6 H 5 CC1 3 +4Ca(OH) 2 = (C6H6000)2Ca-1-3CaC12+4H20.

Bunsen prepared the metal by electrolysing manganese chloride in a porous cell surrounded by a carbon crucible containing hydrochloric acid.

The pure metal readily evolves hydrogen when acted upon by sulphuric and hydrochloric acids, and is readily attacked by dilute nitric acid.

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.

The manganites are amorphous brown solids, insoluble in water, and decomposed by hydrochloric acid with the evolution of chlorine.

The anhydrous chloride, MnCl2, is obtained as a rose-red crystalline solid by passing hydrochloric acid gas over manganese carbonate, first in the cold and afterwards at a moderate red heat.

The hydrated chloride, MnCl2.4H2O, is obtained in rose-red crystals by dissolving the metal or its carbonate in aqueous hydrochloric acid and concentrating the solution.

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.

Strecker, who oxidized guanine with hydrochloric acid and potassium chlorate.

The crude oxide of the metal is obtained from cerite, by evaporating the mineral with strong sulphuric acid, removing excess of acid and dissolving the residue in ice-cold water; sulphuretted hydrogen is passed through the solution, which is then filtered, acidified with hydrochloric acid, and precipitated as oxalate by oxalic acid; the oxalate is then converted into oxide by ignition.

Cold concentrated nitric and sulphuric acids are without action on the metal, but it reacts rapidly with dilute nitric and hydrochloric acids.

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.

A hydrated chloride of composition 2CeC1 3.15H 2 O is also known, and is obtained when a solution of cerous oxide in hydrochloric acid is evaporated over sulphuric acid.

The term alkali is employed in a technical sense for the carbonate and hydrate (of sodium), but since in the Leblanc process the manufacture of sodium sulphate necessarily precedes that of the carbonate, we include this as well as the manufacture of hydrochloric acid which is inseparable from it.

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."

The rise of the ammonia-soda process (since 1870) gradually told upon the Leblanc process, which in consequence has been greatly restricted in Great Britain and Germany, and has become practically extinct in all other countries, except as far as its first part, the manufacture of sodium sulphate and hydrochloric acid, is concerned.

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).

The latter was formerly often constructed as a reverberatory furnace, which is easy to build and to work, but the hydrochloric acid given off here, being mixed with the products of the combustion of the fuel, cannot be condensed to strong acid and is partly, if not entirely, wasted.

This requires more time and fuel than the work in " open " furnaces, but in the muffles the gaseous hydrochloric acid is separated from the fire-gases, just like that evolved in the pot, and can therefore be condensed into strong hydrochloric acid, like the pot-acid.

It is not easy to keep the muffles permanently tight, and as soon as any leakages occur, either hydrochloric acid must escape into the fire-flue, or some fire-gases must enter into the muffle.

The former is decidedly more objectionable than the latter, as it means that uncondensed hydrochloric acid is sent into the air.

In consequence the fire-gases, when arriving there by the chimney shaft (a), have already a good upward draught, and when circulatung round the muffle are at a lower pressure than the gases within the muffle, so that in case of any cracks being formed, no hydrochloric acid escapes into the fire-flues, but vice versa.

This means that the previous manufacture of sulphuric acid in the vitriol-chambers is done away with, but this apparently great simplification is balanced by the great cost of the Hargreaves plant, and by the fact that the whole of the hydrochloric acid is mixed with nine or ten times its volume of inert gases.

The scientific and technical principles of the condensation of hydrochloric acid are now thoroughly well understood, and it is possible to recover nearly the whole of it in the state of strong commercial acid, containing from 32 to 36% of pure hydrochloric acid, although probably the majority of the manufacturers are still content to obtain part of the acid in a weaker state, merely to satisfy the requirements of the law prescribing the prevention of nuisance.

The principles of the condensation, that is of converting the gaseous hydrochloric acid given off during the decomposition of common salt into a strong solution of this gas in water, can be summarized in a few words.

The hydrochloric acid gas, which is always diluted with air, sometimes to a very great extent, must be brought into the most intimate contact possible with water, which greedily absorbs it, forming ordinary hydrochloric acid, and this process must be carried so far that scarcely any hydrochloric acid remains in the escaping gases.

Since the solubility of hydrochloric acid in water decreases with the increase of the temperature, it is necessary to keep the latter down - a task which is rendered somewhat difficult both by the original FIG.

Manufacture of Hydrochloric Acid (commercially also known as " muriatic acid ").

When its deleterious effects upon vegetation, building materials, &c., became better known, and when at the same time an outlet had been found for moderate quantities of hydrochloric acid, most factories made more or less successful attempts to " condense " the gas by absorption in water.

But this was hardly anywhere done to the fullest possible extent, and in those districts where a number of alkali works were located at no great distance from one another, their aggregate escapes of hydrochloric and other acids created an intolerable nuisance.

Gossage to the condensation of hydrochloric acid, are still nearly everywhere in use, frequently combined with a number of stone tanks through which the gas from the furnaces travels before entering the towers, meeting on its way the acid condensed in the tower.

This process is excellent for effecting a complete condensation of the hydrochloric acid as prescribed by the Alkali Acts, and for recovering the bulk of the acid in a tolerably strong state, but less so for recovering nearly the whole of it in the most concentrated state, although even this is occasionally attained.

It is clear that free chlorine must be prepared from hydrochloric acid by oxidizing the hydrogen.

This action must be promoted by heating the mixture, but even then nothing like all of the hydrochloric acid employed is made to act as above, because the attack on the manganese ore requires a certain minimum concentration of the acid.

Formerly, instead of free hydrochloric acid a mixture of common salt and sulphuric acid was sometimes employed, but this is never done on a manufacturing scale now.

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.

It begins with " still-liquor," obtained in the old way from native manganese ore and hydrochloric acid.

This additional lime, which is called the " basis," certainly takes up hydrochloric acid in the next stage of the process, but that causes no more waste of acid than the incomplete action on native manganese ore, mentioned before.

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.

On a small scale it is possible to push the decomposition as far as 90% of the hydrochloric acid, but on the large scale only at most 60% is reached.

The mixture of hydrochloric acid and air is taken directly from the " decomposing-pan " of an ordinary salt-cake furnace, is first cooled down in pipes sufficiently to condense most of the moisture present 1 ?i; \'\` (together with about 8% of the hydrochloric acid), and then passed through a cast-iron superheater and from this into the " decomposer."

The gaseous mixture, issuing from the latter, is washed with water in the usual condensing apparatus, to remove the 40 or 50 parts of hydrochloric acid left unchanged, and can then be immediately employed for the manufacture of chlorate of potash.

The hydrochloric acid from the calcining-furnaces or "roasters" cannot be employed immediately for the Deacon process, as the sulphuric acid always contained in the roaster gases soon " poisons " the contact-substance and renders it inoperative.

This acid must, therefore, be condensed in the ordinary way into liquid hydrochloric acid and formerly could be worked up only by the Weldon process.

The sulphuric acid, of which 6 or 7 parts are used to one of impure liquid hydrochloric acid, is always reserved for usein the same process, by driving off the excess of water in a lead pan, fired from the top, so that the principal expense of the process is that of the fuel required for the last operation.

Mond (1862), but as these required the use of hydrochloric acid, and as they only recovered about half of the Scale T 6.

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 dibrominated product so obtained was then fused with caustic potash, the melt dissolved in water, and on the addition of hydrochloric acid to the solution, alizarin was precipitated.

The melt is dissolved in water and the dyestuff is liberated from the sodium salt by hydrochloric or sulphuric acid, or is converted into the calcium salt by digestion with hot milk of lime, then filtered and the calcium salt decomposed by acid.

The metal is obtained from zinc blende (which only contains it in very small quantity) by dissolving the mineral in an acid, and precipitating the gallium by metallic zinc. The precipitate is dissolved in hydrochloric acid and foreign metals are removed by sulphuretted hydrogen; the residual liquid being then fractionally precipitated by sodium carbonate, which throws out the gallium before the zinc. This precipitate is converted into gallium sulphate and finally into a pure specimen of the oxide, from which the metal is obtained by the electrolysis of an alkaline solution.

It is very heavy, its density being about 11; it inflames when heated in air and is not attacked by alkalis; it readily dissolves in nitric acid and aqua regia, but with difficulty in hydrochloric acid.

When obtained by reduction processes at as low a temperature as possible the finely divided metal so formed is pyrophoric, and according to P. Schutzenberger (Comptes rendus, 1891,113, p. 177) dry hydrochloric acid gas converts this form into nickel chloride and a volatile compound of composition NiHC1.

Hydrochloric and sulphuric acids are almost without action on the metal, but it dissolves readily in dilute nitric acid.

When heated with oxy-acids it dissolves, with evolution of oxygen, and with hydrochloric acid it evolves chlorine.

Knorre (Ber., 1885, 18, p. 169) separate the metals by adding nitros01 3-naphthol in the presence of 50% acetic acid, a precipitate of cobalti nitroso-13-naphthol, [C 10 H 6 0(NO)] 3 Co, insoluble in hydrochloric acid, being formed, whilst the corresponding nickel compound dissolves in hydrochloric acid.

Pinerua separates the metals by taking advantage of the fact that cobalt chloride is soluble in ether which has been saturated with hydrochloric acid gas at low temperature.

Hydrochloric and hydrobromic acids are without action; hydriodic acid only reacts slowly.

Rubidium chloride, RbC1, is formed on burning rubidium in chlorine, or on dissolving the hydroxide in aqueous hydrochloric acid.

It is soluble in a mixture of nitric and hydrofluoric acids, and the powdered metal, in aqua regia, but slowly attacked by sulphuric, hydrochloric and hydrofluoric acids separately; it is also soluble in boiling potash solution, giving a tunstate and hydrogen.

Tungsten dioxide, W02, formed on reducing the trioxide by hydrogen at a red heat or a mixture of the trioxide and hydrochloric acid with zinc, or by decomposing the tetrachloride with water, is a brown strongly pyrophoric powder, which must be cooled in hydrogen before being brought into contact with air.

It is slightly soluble in hydrochloric and sulphuric acids, giving purple solutions.

A crystalline form was obtained by Debray as olive-green prisms by igniting a mixture of sodium tungstate and carbonate in a current of hydrochloric acid gas, and by Nordenskjold by heating hydrated tungstic acid with borax.

Metatungstic acid, H2W4013.7H20, is obtained by decomposing the barium salt with sulphuric acid or the lead salt with hydrochloric acid.

The metatungstates of the alkalis are obtained by boiling normal tungstates with tungstic acid until the addition of hydrochloric acid to the filtrate gives no precipitate.

This salt is obtained by roasting wolfram with sodium carbonate, lixiviating, neutralizing the boiling filtrate with hydrochloric acid and crystallizing at ordinary temperatures.

On boiling gelatinous silica with ammonium polytungstate and evaporating with the occasional addition of ammonia, ammonium silicodecitungstate is obtained as short rhombic prisms. On adding silver nitrate and decomposing the precipitated silver salt with hydrochloric acid, a solution is obtained which on evaporation in a vacuum gives the free acid as a glassy mass.

Its solution liberates chlorine from hydrochloric acid and iodine from potassium iodide.

It is very hygroscopic and with cold water gives the oxide and hydrochloric acid.

It is more hygroscopic than the tetrachloride; and when treated with much water the bulk is at once decomposed into the blue oxide and hydrochloric acid, but an olive-green solution is also produced.

When perfectly pure, the hexachloride is stable even in moist air, but the presence of an oxychloride brings about energetic decomposition; similarly water has no action on the pure compound, but a trace of the oxychloride occasions sudden decomposition into a greenish oxide and hydrochloric acid.

Berthollet, regarding it as being a compound of hydrochloric acid and oxygen, termed it oxygenized muriatic acid.

In the form of alkaline chlorides it is found in sea-water and various spring waters, and in the tissues of animals and plants; while, as hydrochloric acid it is found in volcanic gases.

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.

His method consisted in using magnesia instead of lime for the recovery of the ammonia (which occurs in the form of ammonium chloride in the ammonia-soda process), and then by evaporating the magnesium chloride solution and heating the residue in steam, to condense the acid vapours and so obtain hydrochloric acid.

These cylinders are filled with pills, made of a mixture of magnesia, potassium chloride and fireclay, the object of the potassium chloride being to prevent any formation of hydrochloric acid, which might occur if the magnesia was not perfectly dry.

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.

Perfectly dry hydrochloric acid gas has no action on metals, but in aqueous solution it dissolves many of them with evolution of hydrogen and formation of chlorides.

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.

The solution has a pale yellow colour, and is a strong oxidizing and bleaching agent; it is readily decomposed by hydrochloric acid, with evolution of oxygen.

Hydrochloric acid, sulphuretted hydrogen and sulphurous acid are rapidly oxidized by chloric acid.

The fused mass is then extracted with water to remove potassium chloride, and warmed with hydrochloric acid to remove unaltered chlorate, and finally extracted with water again, when a residue of practically pure perchlorate is obtained.

Sulphuric and hydrochloric acids have little or no action upon it at ordinary temperatures, even when in a fine state of division; but on heating, copper sulphate and sulphur dioxide are formed in the first case, and cuprous chloride and hydrogen in the second.

Ores in which the copper is present as oxide or carbonate are soluble in sulphuric or hydrochloric acids, ferrous chloride, ferric sulphate, ammoniacal compounds and sodium thiosulphate.

The choice of sulphuric or hydrochloric acid depends mainly upon the cost, both acting with about the same rapidity; thus if a Leblanc soda factory is near at hand, then hydrochloric acid would most certainly be employed.

Hydrochloric acid is applied in the same way as sulphuric acid; it has certain advantages of which the most important is that it does not admit the formation of basic salts; its chief disadvantage is that it dissolves the oxides of iron, and accordingly must not be used for highly ferriferous ores.

Copper sulphide may be converted either into the sulphate, which is soluble in water; the oxide, soluble in sulphuric or hydrochloric acid; cupric chloride, soluble in water; or cuprous chloride, which is soluble in solutions of metallic chlorides.

The conversion of copper sulphide into the chlorides may be accomplished by calcining with common salt, or by treating the ores with ferrous chloride and hydrochloric acid or with ferric chloride.

The presence of even a small proportion of hydrochloric acid imparts a brown tint to the deposit.

Cuprous oxide is reduced by hydrogen, carbon monoxide, charcoal, or iron, to the metal; it dissolves in hydrochloric acid forming cuprous chloride, and in other mineral acids to form cupric salts, with the separation of copper.

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.

Its solution in hydrochloric acid readily absorbs carbon monoxide and acetylene; hence it finds application in gas analysis.

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.

Cuprous iodide, Cu 2 l 21 is obtained as a white powder, which suffers little alteration on exposure, by the direct union of its components or by mixing solutions of cuprous chloride in hydrochloric acid and potassium iodide; or, with liberation of iodine, by adding potassium iodide to a cupric salt.

It also absorbs gaseous hydrochloric acid.

Copper sulphate is readily soluble in water, but insoluble in alcohol; it dissolves in hydrochloric acid with a considerable fall in temperature, cupric chloride being formed.

R CH R Ciohc R They are weak bases, and the ring system is readily split by evaporation with hydrochloric acid, or by the action of reducing and oxidizing agents.

For the preparation of the acid the crude argol is boiled with hydrochloric acid and afterwards precipitated as calcium tartrate by boiling with milk of lime, the calcium salt being afterwards decomposed by sulphuric acid.

Bunsen in 1854 electrolysed a thick paste of barium chloride and dilute hydrochloric acid in the presence of mercury, at 10o C., obtaining a barium amalgam, from which the mercury was separated by a process of distillation.

Barium chloride, BaCl 2.2H 2 O, can be obtained by dissolving witherite in dilute hydrochloric acid, and also from heavy spar by ignition in a reverberatory furnace with a mixture of coal, limestone and calcium chloride, the barium chloride being extracted from the fused mass by water, leaving a residue of insoluble calcium sulphide.

The chloride crystallizes in colourless rhombic tables of specific gravity 3.9 and is readily soluble in water, but is almost insoluble in concentrated hydrochloric acid and in absolute alcohol.

Barium and its salts can be readily detected by the yellowishgreen colour they give when moistened with hydrochloric acid and heated in the Bunsenflame, or by observation of their spectra, when two characteristic green lines are seen.

When the secretion of gastric juice is deficient it may be excited by gastric tonics, such as ten grains of bicarbonate of soda and a drachm of compound tincture of gentian in water shortly before meals, and may be supplemented by the administration of pepsin and hydrochloric acid after meals.

Dilute hydrochloric acid is without action on it, but on warming with the concentrated acid, antimony trichloride is formed; it dissolves in warm concentrated sulphuric acid, the sulphate Sb2(S04)3 being formed.

The compound formed, antimoniuretted hydrogen or stibine, SbH 3, may also be prepared by the action of hydrochloric acid on an alloy of antimony and zinc, or by the action of nascent hydrogen on antimony compounds.

It is a white powder, almost insoluble in water, and when volatilized, condenses in two crystalline forms, either octahedral or prismatic. It is insoluble in sulphuric and nitric acids, but is readily soluble in hydrochloric and tartaric acids and in solutions of the caustic alkalies.