Chromic sentence example
It is somewhat readily oxidized; nitric acid gives carbonic and oxalic acids, and chromic acid, carbonic and acetic acids.
Carbon bisulphide slowly oxidizes on exposure to air, but by the action of potassium permanganate or chromic acid it is readily oxidized to carbon dioxide and sulphuric acid.
This substance is transformed into hexachlor-R-pentene oxycarboxylic acid (3) when digested with water; and chromic acid oxidizes this substance to hexachlor-R-pentene (4).
The oxidation, which is effected by chromic acid and sulphuric acid, is conducted in a flask provided with a funnel and escape tube, and the carbon dioxide formed is swept by a current of dry air, previously freed from carbon dioxide, through a drying tube to a set of potash bulbs and a tube containing soda-lime; if halogens are present, a small wash bottle containing potassium iodide, and a U tube containing glass wool moistened with silver nitrate on one side and strong sulphuric acid on the other, must be inserted between the flask and the drying tube.
Ruff (Ber., 18 9 8, 3 1, p. 457) from nitro-di-isobutyl by reducing it to the corresponding hydroxylamino compound with aluminium amalgam and oxidizing this with chromic acid mixture.Advertisement
On oxidation with potassium permanganate it gives homovanillin, vanillin, &c.; with chromic acid in acetic acid solution it is converted into carbon dioxide and acetic acid, whilst nitric acid oxidizes it to oxalic acid.
Chromic acid oxidizes it to acetic acid and ozone oxidizes it to ethyl peroxide.
Styrolene is oxidized by nitric or chromic acids to benzoic acid; reduction gives ethylbenzene; hydrochloric and hydrobromic acids yield a-haloid ethylbenzenes, e.g.
Oxidizing agents convert anthracene into anthraquinone; the production of this substance by oxidizing anthracene in glacial acetic acid solution, with chromic acid, is the usual method employed for the estimation of anthracene.
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.Advertisement
In the alluvial deposits the associated minerals are chiefly those of great density and hardness, such as platinum, osmiridium and other metals of the platinum group, tinstone, chromic, magnetic and brown iron ores, diamond, ruby and sapphire, zircon, topaz, garnet, &c. which represent the more durable original constituents of the rocks whose distintegration has furnished the detritus.
Chromic acid converts it into a-naphthoquinone.
Chromic acid oxidizes it to retene quinone, phthalic acid and acetic acid.
There are three substances which can be relied on more or less to remove this compound, and the gas to be purified may be passed either through acid copper salts, through bleaching powder or through chromic acid.
The second process is one patented by Fritz Ullmann of Geneva, who utilizes chromic acid to oxidize the phosphuretted and sulphuretted hydrogen and absorb the ammonia, and this method of purification has proved the most successful in practice, the chromic acid being absorbed by kieselgiihr and the material sold under the name of "Heratol."Advertisement
Antimony, bismuth, selenium, tellurium, chromic iron ore, tin, nickel, cobalt, vanadium, titanium, molybdenum, uranium and tantalum are produced in the United States in small amounts, but such production in several cases has amounted to only slight discoveries, and in general they are of little importance in the market.
Thus Sainte Claire Deville prepared it as a very hard substance of steel-grey colour, capable of taking a high polish, by strong ignition of chromic oxide and sugar charcoal in a lime crucible.
Sodium and potassium hydroxide solutions precipitate green chromium hydroxide from solutions of chromic salts; the precipitate is soluble in excess of the cold alkali, but is completely thrown down on boiling the solution.
Reducing agents, such as sulphurous acid and sulphuretted hydrogen, convert the chromates into chromic salts.
Chromous chloride, CrC1 2, is prepared by reducing chromic chloride in hydrogen; it forms white silky needles, which dissolve in water giving a deep blue solution, which rapidly absorbs oxygen, forming basic chromic salts, and acts as a very strong reducing agent.Advertisement
Chromic salts are of a blue or violet colour, and apparently the chloride and bromide exist in a green and violet form.
Chromic chloride, CrC1 31 is obtained in the anhydrous form by igniting a mixture of the sesquioxide and carbon in a current of dry chlorine; it forms violet laminae almost insoluble in water, but dissolves rapidly in presence of a trace of chromous chloride; this action has been regarded as a catalytic action, it being assumed that the insoluble chromic chloride is first reduced by the chromous chloride to the chromous condition and the original chromous chloride converted into soluble chromic chloride, the newly formed chromous chloride then reacting with the insoluble chromic chloride.
Solutions of chromic chloride in presence of excess of acid are green in colour.
Chromic bromide, CrBr 3, is prepared in the anhydrous form by the same method as the chloride, and resembles it in its properties.
The hydrated fluoride, CrF3.9H20, obtained by adding ammonium fluoride to cold chromic sulphate solution, is sparingly soluble in water, and is decomposed by heat.Advertisement
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.
It may be condensed to a dark red liquid which is decomposed by moist air into chromic acid and chromic fluoride.
Chromic sulphide, Cr2S3, results on heating chromium and sulphur or on strongly heating the trioxide in a current of sulphuretted hydrogen; it forms a dark green crystalline powder, and on ignition gives the sesquioxide.
Chromic sulphate, Cr2(S04)3, is prepared by mixing the hydroxide with concentrated sulphuric acid and allowing the mixture to stand, a green solution is first formed which gradually changes to blue, and deposits violet-blue crystals, which are purified by dissolving in water and then precipitating with alcohol.
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.Advertisement
By passing ammonia over heated chromic chloride, the nitride, CrN, is formed as a brownish powder.
Cyanogen compounds of chromium, analogous to those of iron, have been prepared; thus potassium chromocyanide, K 4 Cr(CN) 6.2H 2 0, is formed from potassium cyanide and chromous acetate; on exposure to air it is converted into the chromicyanide, K 3 Cr(CN) 6, which can also be prepared by adding chromic acetate solution to boiling potassium cyanide solution.
Chromic thiocyanate, Cr(SCN) 3, an amorphous deliquescent mass, is formed by dissolving the hydroxide in thiocyanic acid and drying over sulphuric acid.
Chromic acid itself showed the bands, but less distinctly, and Soret does not consider the purity of the acid sufficiently proved to allow him to draw any certain conclusions from this observation.
Potash fusion converts it into acetic acid; nitric acid oxidizes it to acetic and oxalic acids; chromic acid mixture to acetaldehyde and acetic acid, and potassium permanganate to a0-dioxybutyric acid.Advertisement
Chromic acid converts it into phosgene (carbonyl chloride, COC1 2).
Chromic acid in glacial acetic acid solution oxidizes it to picene-quinone, picene-quinone carboxylic acid, and finally to phthalic acid.
A similar product is obtained by oxidizing fermentation amyl alcohol with chromic acid.
On oxidation .ith chromic acid it forms a quinone, C 15 H 8 0 2, and an a-diphenylene keto carboxylic acid C E I-4 3.
This can be done most easily by " active " oxygen, such as is present in the peroxides, in chromic or permanganic acid.Advertisement
Nitric acid and chromic acid oxidize them in such a manner that they yield the same products as the alcohols from which they are derived.
It may be prepared by distilling calcium benzoate; by condensing benzene with benzoyl chloride in the presence of anhydrous aluminium chloride; by the action of mercury diphenyl on benzoyl chloride, or by oxidizing diphenylmethane with chromic acid.
Reduction by sodium amalgam converts it into isopropyl alcohol; oxidation by chromic acid gives carbon dioxide and acetic acid.
It is a very stable compound, chromic and nitric acids being without action upon it, whilst the halogens only yield substitution derivatives with difficulty.
Chromic acid oxidizes it to acetic acid and carbon dioxide; potassium permanganate oxidizes it to pyruvic acid; nitric acid to oxalic acid, and a mixture of manganese dioxide and sulphuric acid to acetaldehyde and carbon dioxide.Advertisement
The crude phosphorus is purified by melting under water and then filtering through animal black and afterwards through chamois leather, or by treating it, when molten, with chromic acid or a mixture of potassium bichromate and sulphuric acid; this causes the impurities to rise to the surface as a scum which can be skimmed off.
Oxidation by potassium permanganate gives phthalic acid; whilst chromic acid gives carbon dioxide and water.
The alkaloid is a strong base and is very readily oxidized; chromic acid converts it into normal butyric acid and ammonia; hydrogen peroxide gives aminopropylvalerylaldehyde, NH 2 CH(C 3 11 7) (CH2)3 CHO, whilst the benzoyl derivative is oxidized by potassium permanganate to benzoyl-a-aminovaleric acid, C 6 H 5 CO NH CH(C 3 H 7) (CH 2)3 COOH.
Potassium permanganate oxidizes it to acetylanthranilic acid, [[Hooc(') C 6 H 4 (2)Nh Coch]] 31 while chromic acid oxidizes it to quinaldic acid (quinoline-a-carboxylic acid).
Quinaldic acid (quinoline-a-carboxylic acid) is produced when quinaldine is oxidized by chromic acid.Advertisement
Nitric acid oxidizes it to adipic acid, and chromic acid to cyclo-hexanone.
Chromic acid oxidizes it to benzoic acid and benzaldehyde.
On reduction it yields hexahydrotoluene; oxidation with dilute nitric acid or chromic acid gives benzoic acid; whilst chromyl chloride and water give benzaldehyde.
Sodium amalgam reduces it to acenaphthene; chromic acid oxidizes it to naphthalic acid.
Terephthalic acid, formed by oxidizing para-diderivatives of benzene, or best by oxidizing caraway oil, a mixture of cymene and cuminol, with chromic acid, as almost insoluble in water, alcohol and ether; it sublimes without melting when heated.
Chromic acid converts it into quinone, while chlorates, in the presence of certain metallic salts (especially of vanadium), give aniline black.
Chromium trioxide dissolves readily in water, and the solution is supposed to contain chromic acid, H 2 CrO 4; the salts of this acid are known as the chromates.
By the addition of hydrogen peroxide to a solution of chromic acid, a fine blue coloration due to a perchromic acid is produced which is readily absorbed by shaking out with ether.
The brilliant color of demantoid garnet is due to partial replacement of the silicate by chromic oxide.
He inferred that chromic acid must contain only three atoms of oxygen, as did sulphuric acid SO 3; consequently chromic oxide, which contains half the amount of oxygen, must be Cr 2 O 3, and hence ferric oxide must be Fe203.
Chem., 9, p. 405; To, p. Chromic acid oxidizes phenanthrene, first to phenanthrene-quinone, and then to diphenic acid, HO 2 C C 6 H 4 C 6 H 4 C02H.
Children with diaphragmatic hernias have an increased incidence of chromic lung disease.
Chromic acid and its salts, the chromates and bichromates, can be detected by the violet coloration which they give on addition of hydrogen peroxide to their dilute acid solution, or by the fact that on distillation with concentrated sulphuric acid and an alkaline chloride, the red vapours of chromium oxychloride are produced.
Chromium forms three series of compounds, namely the chromous salts corresponding to CrO, chromous oxide, chromic salts, corresponding to Cr203, chromium sesquioxide, and the chromates corresponding to Cr0,, chromium trioxide or chromic anhydride.