Aqueous Sentence Examples

The aqueous solution is turned bluish black by ferrous sulphate containing a ferric salt.

In aqueous solution it gives a red colour with ferric chloride.

In the ordinary process of soap-making the glycerin remains dissolved in the aqueous liquors from which the soap is separated.

From these results Baeyer concluded that Claus' formula with three para-linkings cannot possibly be correct, for the Q2.5 dihydroterephthalic acid undoubtedly has two ethylene linkages, since it readily takes up two or four atoms of bromine, and is oxidized in warm aqueous solution by alkaline potassium permanganate.

Its aqueous solution has a faint sweet taste, and is dextro-rotatory, the rotation of a fresh solution being about twice that of an old one.

By heating the nitrate it is obtained as hemimorphous pyramids belonging to the hexagonal system; and by heating the chloride in a current of steam as hexagonal prisms. It is insoluble in water; it dissolves readily in all aqueous acids, with formation of salts.

The Central Cordillera consists mainly of crystalline and volcanic rocks, on each side of which are aqueous, in great part Jurassic, strata thrown up almost vertically.

By electrolysing an aqueous solution of the chloride with a mercury cathode, a liquid and a solid amalgam, SrHgn, are obtained; the latter on heating gives a mixture of Sr 2 Hg 5 and SrHg 5, and on distillation an amalgam passes over, and not the metal.

A hydrated dioxide, approximating in composition to SrO 2.8H 2 O, is formed as a crystalline precipitate when hydrogen peroxide is added to an aqueous solution of strontium hydroxide.

It crystallizes in small colourless needles and is easily soluble in water; the concentrated aqueous solution dissolves bromine and iodine readily.

When an aqueous solution of the salt of an alkali metal is electrolysed, the Date.

It is apparent that metallic salts of organic acids would, in aqueous solution, be ionized, the positive ion being the metal, and the negative ion the acid residue.

The quantity of alcohol present in an aqueous solution is determined by a comparison of its specific gravity with standard tables, or directly by the use of an alcoholometer, which is a hydrometer graduated so as to read per cents by weight (degrees according to Richter) or volume per cents (degrees according to Tralles).

Aqueous alcohol becomes turbid when mixed with benzene, carbon disulphide or paraffin oil; when added to a solution of barium oxide in absolute alcohol, a white precipitate of barium hydroxide is formed.

By crystallizing an aqueous solution, red crystals of AuC1 3.2H 2 O are obtained.

Rohrbach's solution, an aqueous solution of barium and mercuric iodides, introduced by Carl Rohrbach, has a density of 3.588.

In modern chemistry alkali is a general term used for compounds which have the property of neutralizing acids, and is applied more particularly to the highly soluble hydrates of sodium and potassium and of the three rarer "alkali metals," caesium, rubidium and lithium, also to aqueous ammonia.

This hypothesis, however, does not accord with the theory of the development of the earth from the state of a sphere of molt s en rock surrounded by an atmosphere of gaseous metals by which the first-formed clouds of aqueous vapour must have been absorbed.

It is manufactured by distilling wood in iron retorts at about 50o C., when an aqueous distillate, containing methyl alcohol, acetone, acetic acid and methyl acetic ester, is obtained.

It is insoluble in acids and exists in several hydrated forms. The osmiates, corresponding to the unknown trioxide 0503, are red or green coloured salts; the solutions are only stable in the presence of excess of caustic alkali; on boiling an aqueous solution of the potassium salt it decomposes readily, forming a black precipitate of osmic acid, H20s04.

It dissolves slowly in water, and the aqueous solution is reduced by most metals with precipitation of osmium.

Aqueous solutions deposit crystals containing 2, 4 or 6 molecules of water.

The aqueous solution of ammonia is very basic in its reactions, and since it is a weak electrolyte, one must assume the solution to contain a certain amount of ammonium hydroxide NH 4 OH, although it is probably chiefly composed of a solution of ammonia in water.

It is soluble in dilute aqueous alcohol, but insoluble in strong alcohol.

The aqueous solution of this salt liberates carbon dioxide on exposure to air or on heating, and becomes alkaline in reaction.

The aqueous solutions of all the carbonates when boiled undergo decomposition with liberation of ammonia and of carbon dioxide.

It is soluble in water, and the aqueous solution on boiling loses ammonia and the acid phosphate NH 4 H 2 PO 4 is formed.

The aqueous solution on boiling loses some ammonia and forms an acid sulphate.

Only one compound of hydrogen and fluorine is known, namely hydrofluoric acid, HF or H 2 F 2, which was first obtained by C. Scheele in 1771 by decomposing fluor-spar with concentrated sulphuric acid, a method still used for the commercial preparation of the aqueous solution of the acid, the mixture being distilled from leaden retorts and the acid stored in leaden or gutta-percha bottles.

The aqueous solution is strongly acid to litmus and dissolves most metals directly.

Eltekow, Ber., 1878, 11, p. 414); by the action of metals on the halogen compounds Cn.H 20 Br 2 i by boiling the aqueous solution of nitrites of the primary amines (V.

It Is Soluble In Water; The Aqueous Solution Gradually Decomposes On Standing, Forming Carbon Dioxide And Sulphuretted Hydrogen.

It forms the acid fluoride KHF 2 when dissolved in aqueous hydrofluoric acid, a salt which at a red heat gives the normal fluoride and hydrofluoric acid.

Iodine dissolves in an aqueous solution of the salt to form a dark brown liquid, which on evaporation over sulphuric acid gives black acicular crystals of the tri-iodide, K1 3.

The carbonate, being insoluble in strong alcohol (and many other liquid organic compounds), is much used for dehydration of the corresponding aqueous preparations.

Abraham Gottlob Werner (1750-1817), the famous exponent of the aqueous theory of earth formation, observed in successive geological formations the gradual approach to the forms of existing species.

The saturated aqueous solution is colourless and fumes strongly on exposure to air; after a time it darkens in colour owing to liberation of iodine.

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.

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.

In the former process it is obtained in the form of a dilute aqueous solution, in which also the colouring matters of the wine, salts, &c., are dissolved; and this impure acetic acid is what we ordinarily term vinegar.

From these acyl derivatives the elements of water are removed, either by simple heating or by boiling their aqueous solution; this elimination is accompanied by the formation of the azoxime ring.

It is a very weak monobasic acid, and the aqueous solution has a very low electric conductivity.

The alkali and alkaline earth cyanides are soluble in water and in alcohol, and their aqueous solution, owing to hydrolytic dissociation, possesses an alkaline character.

Its aqueous solution is not an electrolyte, and consequently does not give the reactions of the mercury and cyanogen ions.

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 in aqueous solution, on stand- ing, gradually passes back to the violet form.

Chromium ammonium sulphate, (NH4)2S04 Cr2(S04)3.24H20, results on mixing equivalent quantities of chromic sulphate and ammonium sulphate in aqueous solution and allowing the mixture to crystallize.

Paschen proved that the emission spectra of water vapour as observed in an oxyhydrogen flame, and of carbon dioxide as observed in a hydrocarbon flame may be obtained by heating aqueous vapour and carbon dioxide respectively to a few hundred degrees above the freezing point.

He definitely established the absorptive power of clear aqueous vapour - a point of great meteorological significance.

To explain the electrical properties of sulphuric acid in aqueous solution, the supposition of three ions, two of hydrogen and one of the chemical group S04, is necessary.

Many metals, of which copper, silver and nickel are types, can be readily won or purified by the electrolysis of aqueous solutions, and theoretically it may be feasible to treat aluminium in an identical manner.

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.

An aqueous solu tion of fuchsine is decolorized on the addition of sulphurous acid, the easily soluble fuchsine sulphurous acid being formed.

The 1 5 diketones of this type, when heated with aqueous ammonia, form pyridine derivatives.

In these solid solutions, as in aqueous ones, the ratios in which the different chemical substances are present are not fixed or definite, but vary from case to case, not per saltum as between definite chemical compounds, but by infinitesimal steps.

The different substances are as it were dissolved in each other in a state which has the indefiniteness of composition, the absolute merging of identity, and the weakness of reciprocal chemical attraction, characteristic of aqueous solutions.

It has also been shown that when different salts of the amine are used, their catalytic influence varies in amount and is almost proportional to their degree of ionization in aqueous solution.

The above methods give a dilute aqueous solution of hydrogen peroxide, which may be concentrated somewhat by evaporation over sulphuric acid in vacuo.

It is a colourless oily liquid of strongly acid reaction; its aqueous solution decomposes on standing and on heating it forms diethyl sulphate and sulphuric acid.

Many tropical plants present on the upper surface of their leaves several layers of compressed cells beneath the epidermis which serve for storage of water and are known as aqueous tissue.

It is easily soluble in water and alcohol, and is thrown out of its aqueous solution by the addition of calcium chloride.

By continued boiling of its aqueous solution it is decomposed into carbon dioxide and glyoxylic acid, C2H404.

It is also decomposed by warm aqueous solutions of caustic alkalis, with evolution of ammonia and carbon dioxide.

Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

By the action of sodium amalgam on an aqueous solution of the acid, benzyl alcohol, tetrahydrobenzoic acid and hexahydrobenzoic acid are formed.

It is only known in aqueous solution.

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 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 forms yellow crystals soluble in water; the aqueous solution on standing gradually depositing a basic salt.

We marvel at the obstinacy with which he, with inadequate mathematical knowledge, opposed the Newtonian theory of light and colour; and at his championship of "Neptunism," the theory of aqueous origin, as opposed to "Vulcanism," that of igneous origin of the earth's crust.

When this takes place in an aqueous solution, the alkaline metal at once reacts with the water, so that a solution of an alkaline hydrate is formed while hydrogen escapes.

Gallium forms colourless salts, which in neutral dilute aqueous solutions are converted on heating into basic salts.

On boiling with aqueous caustic soda, it yields ortho-nitrophenol.

It is readily soluble in acids and in an aqueous solution of ammonia.

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

Tungstic acid, H 2 W0 4, is obtained as H 2 W0 4 H 2 0 by precipitating a tungstate with cold acid; this substance has a bitter taste and its aqueous solution reddens litmus.

It is readily soluble in water, and on boiling the aqueous solution a white hydrate is first deposited which after a time is converted into the trioxide.

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 acid is only known in aqueous solution, and only dilute solutions can be distilled without decomposition.

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.

The aqueous solution can be concentrated in vacuo over sulphuric acid until it contains 40% of chloric acid.

Aqueous solutions of the acid are decomposed in sunlight by uranium salts, with evolution of carbon dioxide and the formation of propionic acid.

The many and extraordinary monuments of aqueous energy include massive columns wrenched from their place in the ceiling and prostrate on the floor; the Hollow Column, 40 ft.

He showed that all conductors liquid and solid might be divided into two classes which he called respectively conductors of the first and of the second class, the first embracing metals and carbon in its conducting form, and the second class, water, aqueous solutions of various kinds, and generally those now called electrolytes.

The copper is readily replaced by iron, a knife-blade placed in an aqueous solution being covered immediately with a bright red deposit of copper.

Common salt precipitates it from aqueous solutions.

The tannin of oak, C/9H16010, which is found, mixed with gallic acid, ellagic acid and quercite, in oak bark, is a red powder; its aqueous solution is coloured dark blue by ferric chloride, and boiling with dilute sulphuric acid gives oak red or phlobaphene.

It may be detected by the addition of an aqueous solution of potassium cyanide, with which it gives a violet-red coloration, due to the formation of isopurpuric acid.

By mixing equal quantities of the two forms in aqueous solution heat is evolved and racemic acid, (C4H606)2.2H20, is obtained.

Barium bromate, Ba(Br03)2, can be prepared by the action of excess of bromine on barytawater, or by decomposing a boiling aqueous solution of loo parts of potassium bromate with a similar solution of 74 parts of crystallized barium chloride.

It crystallizes in the monoclinic system, and separates from its aqueous solution as Ba(Br03)2.H20.

From a supersaturated aqueous solution of borax, the pentahydrate, Na2B407.5H20, is deposited when evaporation takes place at somewhat high temperatures.

Boric acid (q.v.) being only a weak acid, its salts readily undergo hydrolytic dissociation in aqueous solution, and this property can be readily shown with a concentrated aqueous solution of borax, for by adding litmus and then just sufficient acetic acid to turn the litmus red, the addition of a large volume of water to the solution changes the colour back to blue again.

Cochineal owes its tinctorial power to the presence of a substance termed cochinealin or carminic acid, C17H18010, which may be prepared from the aqueous decoction of cochineal.

Antimony trioxide occurs as the minerals valentinite and senarmontite, and can be artificially prepared by burning antimony in air; by heating the metal in steam to a bright red heat; by oxidizing melted antimony with litharge; by decomposing antimony trichloride with an aqueous solution of sodium carbonate, or by the action of dilute nitric acid on the metal.

Antimony trifluoride, SbF 3, is obtained by dissolving the trioxide in aqueous hydrofluoric acid or by distilling antimony with mercuric fluoride.

It forms a fine dark orange powder, insoluble in water, but readily soluble in aqueous solutions of the caustic alkalis and alkaline carbonates.

The rodlets after three hours' culture in a drop of aqueous become septate later, and spores are developed in the segments.

Ferric chloride colours its aqueous solution a dark violet, and bromine water precipitates tribromresorcin.

It crystallizes in shining rhombic prisms from its aqueous solution and as delicate needles from alcohol.

The leading solvents are aqueous solutions of thiosulphates, unsystematically but generally termed hyposulphites.

A colloidal selenium was obtained by C. Paal and C. Koch (Ber., 1905, 38, p. 526) by reducing selenious acid dissolved in an aqueous solution of sodium protalbate with hydrazine hydrate and hydrochloric acid, the precipitate obtained being then dissolved in sodium carbonate.

Its aqueous solution is unstable, gradually depositing red selenium on standing.

Ferric chloride gives a green coloration with the aqueous solution, whilst the alkaline solution rapidly changes to a green and finally to a black colour on exposure to the air.

For oxidizing purposes bromine is generally employed in aqueous and in alkaline solutions, one of its most important applications being by Emil Fischer (Berichte, 1889, 22, p. 362) in his researches on the sugars.

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.

The aqueous solution is light yellow in colour, and possesses strong bleaching properties.

They are stable towards aqueous alkalis, but on digestion with moist silver oxide yield the phosphonium hydroxides, which are stronger bases than the caustic alkalis.

It is a monobasic acid forming salts which are permanent in air, but which are gradually oxidized in aqueous solution.

The aqueous solution may be boiled without decomposition, but on concentration it yields phosphorous and phosphoric acids.

Methyl conine, C 9 H 19 N or C8H14 N(CH3), is synthesized from conine and an aqueous solution of potassium methyl sulphate at

It may also be produced by heating an aqueous solution of di-iodosalicylic acid with excess of alkaline carbonate, by acting on dibromosalicylic acid with moist silver oxide, and by other methods.

Ordinary sulphuric acid, H 2 SO 4, may be prepared by dissolving sulphur trioxide in water, a reaction accompanied by a great evolution of heat; by the gradual oxidation of an aqueous solution of sulphur dioxide, a fact which probably explains the frequent occurrence of sulphuric acid in the natural waters rising in volcanic districts; or by deflagrating a mixture of sulphur and nitre in large glass bells or jars, absorbing the vapours in water and concentrating the solution.

The behaviour of aqueous solutions of sulphuric acid is very interesting.

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.

Many oxychlorides are known; soluble forms are obtained by dissolving precipitated ferric hydrate in ferric chloride, whilst insoluble compounds result when ferrous chloride is oxidized in air, or by boiling for some time aqueous solutions of ferric chloride.

Alcohol also throws down the salt from aqueous solution, the composition of the precipitate varying with the amount of salt and precipitant employed.

The thorough saturation of the narrow space with aqueous vapour, and the presence of drain water in the cutting, were probably their chief preservatives - assisted by the high even temperature always found in the deeper headings of coal mines, and by the enormous compression of the confined air.

Its aqueous solution is strongly alkaline, and with acids it forms well-defined stable salts.

Metavanadic acid is obtained in the form of yellow scales by boiling copper vanadate with an aqueous solution of sulphur dioxide.

His aspect of the heavens told him that in that year three planets would meet in the aqueous sign of Pisces.

The opinion that it is of aqueous origin (and probably dates from the close of the glacial time) has the weight of authority.

Ferric chloride gives a bluishviolet coloration with the aqueous solution.

It is dextrorotatory in aqueous or alkaline solution, and laevo-rotatory in acid solution.

Concentration of the aqueous solution in a desiccator gives a deposit of crystals of a very deliquescent salt, H21n2(S04)4.8H20.

The fat is then drawn off the aqueous (gluey) layer, and strained through sieves or filters.

On standing, the distillate separates into two layers, an aqueous and an oily layer, the oil floating on or sinking through the water according to its specific gravity.

They are odourless and tasteless, and some yield clear aqueous solutions - the real gums - while others swell up and will not percolate filter paper - the vegetable mucilages.

The acid is a "weak" acid, being ionized only to a very slight extent in dilute aqueous solution.

The vaccine is suspended in the aqueous phase of an oil adjuvant emulsion.

The aqueous solution is slightly alkaline, with a pH about 8.2.

Usually the pH is made more alkaline by hydrolysis of urea (NH 2 CONH 2) in boiling aqueous solution.

Ammonia and its aqueous solution form complexes called amines with many salts.

This very aqueous route has only been partially surveyed.

Healthy Direct's Sage tablets have been formulated using aqueous (water-based) extraction methods rather than alcohol-based.

Know how to distinguish alkenes (as unsaturated hydrocarbons) from alkanes (as saturated hydrocarbons) using addition reactions with aqueous bromine.

Aqueous carboxymethyl cellulose solutions are used, occasionally with the inclusion of bovine serum.

This clean, nearly colorless, concentrated aqueous solution will benefit all of your plants.

Also, due to their extended conformation, arabinoxylans exhibit a very high viscosity in aqueous solution.

Subsequent acid oxidation of the type used on the original material again yielded an aqueous dispersion.

In a 0.1 M aqueous solution of NaCl the average distance between the fully dissociated ions is about 0.8 nm.

Know that aqueous solutions of ionic compounds will also undergo electrolysis.

For particles in aqueous solution the interparticle forces are predominantly electrostatic in origin.

If you are not prescribed an emollient you can buy a big tub of Aqueous Cream for around £ 3 at most pharmacies.

Different brands of simple topical emollients such as aqueous cream, oily cream and emulsifying ointment should not influence the efficacy of the treatment.

Assuming the corneal thickness = 1 unit, assess the width of the " aqueous gap " from corneal endothelium to iris.

At 50% aqueous ethanol, all the hydrocarbons were found to move unimpeded through the columns.

Positive patch test reactions to the latex and to an aqueous extract of the leaves and latex were observed.

A more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt.

The eyes are especially sensitive to microwaves, whose energy is readily absorbed by the internal fluid, the aqueous humor.

They use nickel and cadmium as electrodes and aqueous potassium hydroxide as electrolyte.

In addition, the alcohol-based lotions are more effective than the aqueous lotions.

The samples were extracted with 80 per cent aqueous methanol at room temperature, using a procedure based on that of Barnes et al.

Products such as aqueous cream and emulsifying ointment can be used as soap substitutes for hand washing or when bathing.

For neurolytic blocks (arterial insufficiency) 3 - 5 ml 6% aqueous phenol is injected.

Further impurities are removed using aqueous sodium hydroxide to neutralize free acids and steam which removes volatile compounds.

Sulfur hexafluoride is an inert, innocuous gas, poorly soluble in aqueous solutions.

The process may be accelerated by exhausting the desiccator; this so-called vacuum desiccation is especially suitable for the concentration of aqueous solutions of readily decomposable substances.

Berglund (Berichte, 18 74, 7, p. 469), in aqueous solution, by dissolving ammonium cobaltocobaltisulphite (NH4)2C02 [(S03) 6 'C02] 14H 2 O in dilute hydrochloric or nitric acids, or by decomposition of its silver salt with hydrochloric acid.

By the addition of excess of ammonia to its aqueous solution, in the complete absence of air, a blue precipitate of a basic nitrate of the composition 6C00 N 2 0 6 5H 2 O is obtained.

From its aqueous solution, concentrated hydrochloric acid precipitates hydrocobalticyanic acid, H 3 Co(CN) 61 as a colourless solid which is very deliquescent, and is not attacked by concentrated hydrochloric and nitric acids.

The above series of salts show striking differences in their behaviour towards reagents; thus, aqueous solutions of the luteo chlorides are strongly ionized, as is shown by their high electric conductivity; and all their chlorine is precipitated on the addition of silver nitrate solution.

The aqueous solution, however, does not show the ordinary reactions of cobalt or of ammonia, and so it is to be presumed that the salt ionizes into [Co(NH 3) 6] and 3C1'.

Thus, Pasteur showed that Penicillium glaucum, when grown in an aqueous solution of ammonium racemate, decomposed the dextro-tartrate, leaving the laevotartrate, and the solution which was originally inactive to polarized light became dextro-rotatory.

It dissolves readily in water and the aqueous solution decomposes on standing; a dark-brown flocculent precipitate of azulmic acid, C 4 H 5 N 5 0, separating whilst ammonium oxalate, urea and hydrocyanic acid are found in the solution.

All tadpoles are provided with more or less distinct lines of muciferous sensory crypts or canals, which stand in immediate relation to the nerve branches and are regarded as organs of a special sense possessed by aquatic vertebrates, feeling, in its broadest sense, having been admitted as their possible use, and the function of determining waves of vibration in the aqueous medium having been suggested.

The aqueous vapour in the atmosphere is transparent to luminous but opaque to obscure heat-rays.

Large quantities of carbonate used to be manufactured from the aqueous residue left in the distillation of beet-root spirit, i.e.

Chem., 1866, 9 8, p. 340); by the action of chlorine on steam at a bright red heat; by the decomposition of hydrogen peroxide by bleaching powder, manganese dioxide, potassium ferricyanide in alkaline solution, or potassium permanganate in acid solution; by heating barium peroxide with an aqueous solution of potassium ferricyanide (G.

Fructose without other additives, was proposed by Lillie as a concentrated syrupy solution useful as an aqueous mountant.

Nail-patella syndrome is thought to be associated with open-angle glaucoma, a condition caused by blockage of the outflow of fluid (aqueous humor) from the front chamber of the eyes.

Fluid produced within the eye (aqueous humor) cannot exit normally.

The allergen is applied to the skin as an aqueous extract, usually on the back, forearms, or top of the thighs.

They form yellow or bronze-coloured crystals, which decompose on boiling their aqueous solution.

The ortho-acid, in the form of its aqueous solution, is sometimes used as an antiseptic, under the name of aseptol.

Its aqueous solution gradually decomposes with evolution of oxygen, behaves as a strong oxidant, and liberates iodine from potassium iodide.

The free acid is obtained (in dilute aqueous solution) by the addition of dilute sulphuric acid to an aqueous solution of the barium salt.

It is only stable in dilute aqueous solution, for on concentration the acid decomposes with formation of sulphuric acid, sulphur dioxide and sulphur.

It behaves as a strong oxidant and in aqueous solution is slowly hydrolysed.

The fouling of the air that results from the steam-engine, owing to the production of carbonic acid gas and of sulphurous fumes and aqueous vapour, is well known, and its use is now practically abandoned for underground working.

Hess now observed that in the process of mixing such neutral solutions no thermal effect was produced - that is, neutral salts in aqueous solution could apparently interchange their radicals without evolution or absorption of heat.

Thomsen by direct experiment found that the heat-capacity of a dilute aqueous solution diverged in general less than i per cent.

It has already been stated that the heats of neutralization of acids and bases in aqueous solution are additively composed of two terms, one being constant for a given base, the other constant for a given acid.

It forms a characteristic explosive silver salt on the addition of ammoniacal silver nitrate to its aqueous solution, and an amorphous precipitate which explodes on warming with ammoniacal cuprous chloride.

Ferric chloride colours its aqueous solution violet.

Bromine water in dilute aqueous solution gives a white precipitate of tribromophenol-bromide C 6 H 2 Br 3.

It is somewhat volatile at ordinary temperature, and its aqueous solution possesses a strongly acid reaction.

This leads us to examine more closely the part played by water in the electrolysis of aqueous solutions.

If an aqueous solution of methyl acetate be allowed to stand, a slow decomposition goes on.

The temperature coefficient of conductivity has approximately the same value for most aqueous salt solutions.

Aqueous non-oxidizing acids generally have little or no action on lead in the absence of air.

Lead nitrate, Pb(N03)2, is obtained by dissolving the metal or oxide in aqueous nitric acid; it forms white crystals, difficultly soluble in cold water, readily in hot water and almost insoluble in strong nitric acid.

Lead acetate, Pb(C2H302)2.3H20 (called "sugar" of lead, on account of its sweetish taste), is manufactured by dissolving massicot in aqueous acetic acid.

It gives mono-metallic salts of the type NC NHM when treated with aqueous or alcoholic solutions of alkalis.

Silicofluoric acid, H2SiF6, is obtained as shown above, and also by the action of sulphuric acid on barium silicofluoride, or by absorbing silicon fluoride in aqueous hydrofluoric acid.

The anhydrous acid is not known, since on evaporating the aqueous solution it gradually decomposes into silicon fluoride and hydrofluoric acid.

Triethyl silicol, (C2H5),Si OH, is a true alcohol, obtained by condensing zinc ethyl with silicic ester, the resulting substance of composition, (C2H5)3 SiOC2H51 with acetyl chloride yielding a chloro-compound (C2H5)3SiC1, which with aqueous ammonia yields the alcohol.

Silicobenzoic acid, C 6 H 5 S10.0H, results from the action of dilute aqueous ammonia on phenyl silicon chloride (obtained from mercury diphenyl and silicon tetrachloride).

The acid carbonates of the alkali metals can be prepared by saturating an aqueous solution of the alkaline hydroxide with carbon dioxide, M OH+ C02= Mhco 3, and from these acid salts the normal salts may be obtained by gentle heating, carbon dioxide and water being produced at the same time, 2Mhco 3 = M2C03+H02+C02.

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

A group (C) may be formed of mercury, silver, gold and platinum, which are not touched by either aqueous acid in any circumstances.

Of metals not decomposing liquid pure water, only a few dissolve in aqueous caustic potash or soda, with evolution of hydrogen.

But of the rest the majority, when treated with boiling sufficiently strong alkali, are attacked at least superficially; of ordinary metals only gold, platinum, and silver are perfectly proof against the reagents under consideration, and these accordingly are used preferably for the construction of vessels intended for analytical operations involving the use of aqueous caustic alkalis.

Iron, which stands so well against aqueous alkalis, is most violently attacked by the fused reagents.

In many of these the application of heat is necessary to bring the substances used into the liquid state for the purpose of electrolysis, aqueous solutions being unsuitable.

A better method is Wohler's, in which the finely powdered mineral is fused with twice its weight of potassium carbonate in a platinum crucible, the melt powdered and treated in a platinum basin with aqueous hydrofluoric acid.

They are ionized in aqueous solution to a much greater extent than ammonia, the quaternary ammonium bases being the most ionized, and the secondary bases being more strongly ionized than the primary or tertiary bases.

By warming its aqueous solution with an excess of silver oxide it is converted into tetramethylammonium hydroxide, N(CH3)40H, which crystallizes in hygroscopic needles, and has a very alkaline reaction.

On the other hand, they are much weaker bases than the aliphatic amines, their salts undergoing hydrolytic dissociation in aqueous solution.

The aqueous product is then dehydrated with potash or lime.

All the ammonia contained in an aqueous solution of the gas may be expelled by boiling.

Cobalt fluoride, CoF 2.2H 2 0, is formed when cobalt carbonate is evaporated with an excess of aqueous hydrofluoric acid, separating in rose-red crystalline crusts.

The lake is nowhere of great depth, and about midway numerous mud-banks, marshes, islands and dense growths of aqueous plants stretch across its surface.

The alkaloid is obtained from an aqueous extract of tobacco by distillation with slaked lime, the distillate being acidified with oxalic acid, concentrated to a syrup and decomposed by potash.

It is also readily soluble in solutions of the caustic alkalis, slightly soluble in aqueous ammonia solution, and almost insoluble in sodium carbonate solution.

Berthelot, on the other hand, assumed that the heat-capacity of an aqueous solution is equal to that of an equal volume of water, and calculated his results on this assumption, which involves much the same uncertainty as that of Thomsen.

Its viscid character, and its non-liability to dry and harden by exposure to air, also fit it for various other uses, such as lubrication, &c., whilst its peculiar physical characters, enabling it to blend with either aqueous or oily matters under certain circumstances, render it a useful ingredient in a large number of products of varied kinds.

In aqueous solutions, for instance, a few hydrogen (H) and hydroxyl (OH) ions derived from the water are always present, and will be liberated if the other ions require a higher decomposition voltage and the current be kept so small that hydrogen and hydroxyl ions can be formed fast enough to carry all the current across the junction between solution and electrode.

An aqueous solution readily dissolves lead oxide, with formation of a strongly alkaline solution containing basic acetates (Acetum Plumbi or Saturni).

They are yellowish-red solids, which behave as weak bases, their salts undergoing hydrolytic dissociation in aqueous solution.

Cadmium sulphate, CdSO 4, is known in several hydrated forms; being deposited, on spontaneous evaporation of a concentrated aqueous solution, in the form of large monosymmetric crystals of composition 3CdSO 4.8H 2 O, whilst a boiling saturated solution, to which concentrated sulphuric acid has been added, deposits crystals of composition CdSO 4 4H 2 0.

Thioaldehydes are also known, and are obtained by leading sulphuretted hydrogen into an aqueous solution of acetaldehyde.

These are knocked off, ground up with water, freed from metal-particles by elutriation, and the paste of white lead is allowed to set and dry in small conical forms. The German method differs from the Dutch inasmuch as the lead is suspended in a large chamber heated by ordinary means, and there exposed to the simultaneous action of vapour of aqueous acetic acid and of carbon dioxide.

The aqueous solution of the acid is fairly stable at ordinary temperatures.