How to use Oxidation in a sentence
In practice this oxidation process is continued until the whole of the oxygen is as nearly as possible equal in weight to the sulphur present as sulphide or as sulphate, i.e.
On reduction glucose appears to yield the hexahydric alcohol d-sorbite, and on oxidation d-gluconic and d-saccharic acids.
During recent years an immense number of ringed or cyclic compounds have been discovered, which exhibit individual characters more closely resembling benzene, naphthalene, &c. than purely aliphatic substances, inasmuch as in general they contain double linkages, yet withstand oxidation, and behave as nuclei, forming derivatives in much the same way as benzene.
The transformation is not one of the oxidation of a hexamethylene compound to a benzenoid compound, for only two hydrogen atoms are removed.
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.Advertisement
It is very hygroscopic, dissolves readily in water, and rapidly undergoes oxidation on exposure to air.
If we accept Kekule's formula for the benzene nucleus, then we may expect the double linkages to be opened up partially, either by oxidation or reduction, with the formation of di-, tetra-, or hexa-hydro derivatives, or entirely, with the production of open chain compounds.
This is obviously unsymmetrical, consisting of an aliphatic and an aromatic nucleus; Claus explained the formation of the same phthalic acid from the oxidation of either nucleus by supposing that if the aromatic group be oxidized, the aliphatic residue assumes the character of a benzene nucleus.
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.
When kept fused in the presence of air lead readily takes up oxygen, with the formation at first of a dark-coloured scum, and then of monoxide PbO, the rate of oxidation increasing with the temperature.Advertisement
It is found in the volatile oils of Spiraea, and can be obtained by the oxidation of the glucoside salicin, (C13H1807), which is found in willow bark.
Rhombic sulphur may be obtained artificially by slowly crystallizing a solution of sulphur in carbon bisulphide, or, better, by exposing pyridine saturated with sulphuretted hydrogen to atmospheric oxidation (Ahrens, Ber., 1890, 23, p. 2708).
In this latter reaction the deep yellow solution obtained is exposed to air when the calcium polysulphide formed is gradually converted into thiosulphate by oxidation, and the calcium salt thus formed is converted into the sodium salt by sodium carbonate or sulphate.
The phlogistic theory, which pervaded the chemical doctrine of this period, gave rise to continued study of the products of calcination and combustion; it thus happened that the knowledge of oxides and oxidation products was considerably developed.
Zincke; and his researches have led to the discovery of many chlorinated oxidation products which admit of decomposition into cyclic compounds containing fewer carbon atoms than characterize the benzene ring, and in turn yielding openchain or aliphatic compounds.Advertisement
Methods depending upon oxidation in the presence of a contact substance have come into favour during recent years.
There is thus a minimum circulation in the greater depths causing there uniformity of temperature, an absence of the circulation of oxygen by other means than diffusion, and a protection of the sulphuretted hydrogen from the oxidation which takes place in homologous situations in the open ocean.
A December 1999 American Journal of Clinical Nutrition Study concluded that "Green tea has thermogenic properties and promotes fat oxidation beyond that explained by its caffeine content per se."
Its tetramethyl-diamino derivative, which is formed by condensing formaldehyde with dimethyl-meta-aminophenol and subsequent elimination of water from the resulting diphenyl methane derivative, is the leuco base of pyronine, into which it passes by oxidation.
The study of the action of ozone on caoutchouc has thrown new light on the complex question of the chemical structure of this substance, and discloses relationships with the sugars and other carbohydrates from certain of which levulinic acid is obtained by oxidation.Advertisement
Piperic acid differs from piperonylic acid by the group C4H 4, and it was apparent that these carbon atoms must be attached to the carbon atom which appears in the carboxyl group of piperonylic acid, for if they were directly attached to the benzene ring polycarboxylic acids would result in oxidation.
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.
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.
By the action of alkalis it is converted into iso-eugenol, which on oxidation yields vanillin, the odorous principle of vanilla.
Strong or weak solutions of these substances also decompose it, producing some alkali nitrate and nitrite, the cellulose molecule being only partially restored, some quantity undergoing oxidation.Advertisement
Koerner (Ber., 1884, 17, p. 203) by condensing ortho-nitrobenzaldehyde with aniline, the resulting ortho-nitro-para-diamino-triphenylmethane being reduced to the corresponding orthoamino compound, which on oxidation yields chrysaniline.
These substances condense to form tetra-aminotriphenylmethane, which, on heating with acids, loses ammonia and yields diaminodihydrophenylacridine, from which benzoflavin is obtained by oxidation.
Oxidation may be effected by the addition to the glass mixture of a substance which gives up oxygen at a high temperature, such as manganese dioxide or arsenic trioxide.
On fusion with alkaline carbonates and hydroxides it undergoes oxidation to silica which dissolves on the excess of alkali yielding an alkaline silicate.
For commercial purposes iron is universally employed and works well; but it is not available analytically, because a superficial oxidation of the empty part of the vessel (by the water and air) cannot be prevented.Advertisement
Benzene is very stable to oxidants, in fact resistance to oxidation is a strong characteristic of the benzene ring.
The trioses are the aldehyde and ketone mentioned above as oxidation products of glycerin.
Thus Wohl prepared l-threose from l-xylose and l-erythrose from l-arabinose, and Ruff obtained d- and l-erythrose from d- and l-arabonic acids, the oxidation products of d- and l-arabinoses.
Impure inactive forms result on the polymerization of glycollic aldehyde and also on the oxidation of erythrite, a tetrahydric alcohol found in some lichens.
The plane projection of molecular structures which differ stereochemically is discussed under Stereoisomerism; in this place it suffices to say that, since the terminal groups of the hexaldose molecule are different and four asymmetric carbon atoms are present, sixteen hexaldoses are possible; and for the hexahydric alcohols which they yield on reduction, and the tetrahydric dicarboxylic acids which they give on oxidation, only ten forms are possible.Advertisement
Since both d-glucose and d-gulose yield the same active (d) saccharic acid on oxidation, the configuration of this and the corresponding /-acid must be sought from among those numbered 5-10 in the above table.
These nitrates generally occur as efflorescences caused by the oxidation of nitrogenous matter in the presence of the alkalies and alkaline earths.
To the chemical changes, mainly oxidation, which go on in this juice while it is exposed to the air, the characteristic aroma and flavour of Perique tobacco are mainly due.
To this end he examined such immediate vital products as blood, bile and urine; he analysed the juices of flesh, establishing the composition of creatin and investigating its decomposition products, creatinin and sarcosin; he classified the various articles of food in accordance with the special function performed by each in the animal economy, and expounded the philosophy of cooking; and in opposition to many of the medical opinions of his time taught that the heat of the body is the result of the processes of combustion and oxidation performed within the organism.
Concentrated nitric acid attacks them violently, producing various oxidation products, but if the amino group be "protected" by being previously acetylated, then nitro derivatives are obtained.Advertisement
The same inventor has patented the application of electrolysed chlorides to the purification of starch by the oxidation of less stable organic bodies, to the bleaching of oils, and to the purification of coal gas, spirit and other substances.
Acids frequently result as oxidation products, being almost invariably formed in all cases of energetic oxidation.
There are certain reactions, however, in which oxidation can be successfully applied to the synthesis of acids.
An important oxidation synthesis of aromatic acids is from hydrocarbons with aliphatic side chains; thus toluene, or methylbenzene, yields benzoic acid, the xylenes, or dimethyl-benzene, yield methyl-benzoic acids and phthalic acids.
Ketones, secondary alcohols and tertiary alcohols yield a mixture of acids on oxidation.Advertisement
Traces of ethyl alcohol in solutions are detected and estimated by oxidation to acetaldehyde, or by conversion into iodoform by warming with iodine and potassium hydroxide.
Oxidation of ethyl alcohol gives acetaldehyde and acetic acid.
Hence the diminished oxidation of the tissues, which leads to the accumulation of unused fat and so to the obesity which is so often seen in those who habitually take much alcohol.
Alcohol also diminishes the oxidation which is the main source of the body-heat.
The raised temperature appears to facilitate the oxidation of the substance, so that quantities may be taken and completely utilized which would completely intoxicate the individual had his temperature been normal.Advertisement
Matthiessen and Bose obtained large crystals of the alloy Au 2 Sn 5, having the colour of tin, which changed to a bronze tint by oxidation.
On oxidation it yields ortho-carboxy-hydrocinnamic acid, HO 2 C C 6 H 4 CH 2 CH 2 C02H.
Bismuth dioxide, BiO or Bi 2 O 2, is said to be formed by the limited oxidation of the metal, and as a brown precipitate by adding mixed solutions of bismuth and stannous chlorides to a solution of caustic potash.
Jacobsen on some occasions found water in the surface layers of the Baltic supersaturated with oxygen, which he ascribed to the action of the chlorophyll in vegetable plankton; in other cases when examining the nearly stagnant water from deep basins he found a deficiency of oxygen due no doubt to the withdrawal of oxygen from solution, by the respiration of the animals and by the oxidation of the deposits on the bottom.
The term is more customarily given to productions of flame such as we have in the burning of oils, gas, fuel, &c., but it is conveniently extended to other cases of oxidation, such as are met with when metals are heated for a long time in air or oxygen.
The term "spontaneous combustion" is used when a substance smoulders or inflames apparently without the intervention of any external heat or light; in such cases, as, for example, in heaps of cotton-waste soaked in oil, the oxidation has proceeded slowly, but steadily, for some time, until the heat evolved has raised the mass to the temperature of ignition.
Oxidation gives formaldehyde, formic acid and carbonic acid; chlorine and bromine react, but less readily than with ethyl alcohol.
Nitric acid and lower nitrogen oxides are present, being formed by electrical discharges, and by the oxidation of atmospheric ammonia by ozone.
In England gold and copper blanks are protected from oxidation, and after their passage through the furnace are merely washed in colanders with water and dried with sawdust in a rotating drum.
Cod-liver oil has the further peculiarity of being more readily oxidizable than any other oil; an obviously valuable property when it is remembered that the entire foodvalue of oils depends on their oxidation.
A faint smell of acetylene may be perceived during the oxidation in moist air; this is probably due to traces of calcium carbide.
Benzoquinone (para) or ordinary quinone, C 6 H 4 0 2, is formed by the oxidation of aniline with sodium bichromate and sulphuric acid.
Quinhydrone, C 6 H40 2 -C 6 H 4 (OH) 2, is formed by the direct union of quinone and hydroquinone or by careful oxidation of hydroquinone with ferric chloride solution.
It was found, however, that if the cooling be not sufficiently rapid explosions occurred owing to the combination of the metal with carbon monoxide (produced in the oxidation of the charcoal) to form the potassium salt of hexaoxybenzene.
Methyl and dimethylalloxans are also known, the former being obtained on oxidation of methyl uric acid, and the latter on oxidation of caffeine.
The salts, known as the iodates, can be prepared by the action of the acid on a base, or sometimes by the oxidation of iodine in the presence of a base.
Acetic acid (in the form of vinegar) was known to the ancients, who obtained it by the oxidation of alcoholic liquors.
When heated in contact with air they undergo a certain amount of oxidation, being converted to some extent into the corresponding cyanate.
It is an unsaturated compound, and on oxidation with potassium permanganate gives succinic acid.
Sodium in amyl alcohol solution reduces it to hydroecgonidine C9H15N02, while moderate oxidation by potassium permanganate converts it into norecgonine.
Oxidation is better effected (if a very high temperature be not required) the farther the substance is from the apex of the inner cone, for the air has thus freer access.
They may be prepared by the reduction of nitro compounds in alkaline solution (using zinc dust and alkali, or a solution of an alkaline stannite as a reducing agent); by oxidation of hydrazo compounds; or by the coupling of a diazotized amine and any compound of a phenolic or aminic type, provided that there is a free para position in the amine or phenol.
Mitscherlich in 1834, may be prepared by reducing nitrobenzene in alcoholic solution with zinc dust and caustic soda; by the condensation of nitrosobenzene with aniline in hot glacial acetic acid solution; or by the oxidation of aniline with sodium hypobromite.
They may also be obtained by the oxidation of azo compounds.
Those not containing a nitro group may be prepared by the oxidation of the corresponding mixed hydrazo compounds with mercuric oxide.
They are closely related to the terpenes, with which they occur in plants and of which they are oxidation products.
Abietic acid can be extracted from colophony by means of hot alcohol; it crystallizes in leaflets, and on oxidation yields trimellitic, isophthalic and terebic acid.
Gentler means of oxidation have since been found for bleaching tussur to a fairly pale ground.
In spite of the fact that C. Fredenhagen has recently attempted to revive Pringsheim's original views in a modified form - substituting oxidation for reduction - we may consider it as generally admitted that the origin of spectra lies with vibrating systems which are definite and not dependent on the method of incitement.
The oxidation of benzaldehyde to benzoic acid when exposed to air is not one of ordinary oxidation, for it has been observed in the case of many compounds that during such oxidation, as much oxygen is rendered " active " as is used up by the substance undergoing oxidation; thus if benzaldehyde is left for some time in contact with air, water and indigosulphonic acid, just as much oxygen is used up in oxidizing the indigo compound as in oxidizing the aldehyde.
A few concordant determinations of density having been effected, the question was at first regarded as disposed of, until the thought occurred that it might be desirable to try also the more usual method of preparation in which the oxygen is removed by actual oxidation of copper without the aid of ammonia.
It is formed when a stream of electric sparks is passed through moist air, and in the oxidation ',of nitrogenous matter in the presence of water.
Hofmann having previously shown that oxidation of pure aniline alone or of pure toluidine yielded no fuchsine, whilst oxidation of a mixture of aniline and para-toluidine gave rise to the fine red dyestuff para-fuchsine (pararosaniline hydrochloride) CH 3 C 6 H 4 NH 2 +2C 6 H 5 NH 2 +30 = HOC(C 6 H 4 NH 2) 3 +2H20.
The reverse series of operations was also carried out by the Fischers, triphenylmethane being nitrated, and the nitro compound then reduced to triaminotriphenylmethane or paraleucaniline, which on careful oxidation is converted into the dyestuff.
On oxidation, the molecule is split at the carbonyl group and a mixture of acids is obtained.
In 1856 Bessemer not only invented his extraordinary process of making the heat developed by the rapid oxidation of the impurities in pig iron raise the temperature above the exalted melting-point of the resultant purified steel, but also made it widely known that this steel was a very valuable substance.
Thus, first, for the brittle glass-hard cementite there is gradually substituted the relatively harmless temper graphite; and, second, even this is in part removed by surface oxidation.
But this basicity implies that for each part of the silica or silicic acid which inevitably results from the oxidation of the silicon of the pig iron, the cinder shall contain some three parts of iron oxide, itself a valuable and expensive substance.
In the basic Bessemer process phosphorus is readily removed by oxidation, because the product of its oxidation, phosphoric acid, P 2 O 5, in the presence of an excess of base forms stable phosphates of lime and iron which pass into the slag, making it valuable as an artificial manure.
But this dephosphorization by oxidation can be carried out only in the case slag is basic. If it is acid, i.e.
Mushet's aid was certainly valuable, but not more than Goransson's, who, besides thus offering a preventive of redshortness, further helped the process on by raising its temperature by the simple expedient of further subdividing the blast, thus increasing the surface of contact between blast and metal, and thus in turn hastening the oxidation.
The oxidation of manganese is capable of generating a very high temperature, but it has the very serious disadvantage of causing such thick clouds of smoky oxide of manganese as to hide the flame from the blower, and prevent him from recognizing the moment when the blow should be ended.
The slag, in order that it may have such an excess of base that this will retain the phosphoric acid as fast as it is formed by the oxidation of the phosphorus of the pig iron, and prevent it from being re-deoxidized and re-absorbed by the iron, should, according to von Ehrenwerth's rule which is generally followed, contain enough lime to form approximately a tetra-calcic silicate, 4CaO,S10 2 with the silica which results from the oxidation of the silicon of the pig iron and tri-calcic phosphate, 3CaO,P205, with the phosphoric acid which forms. The danger of this " rephosphorization " is greatest at the end of the blow, when the recarburizing additions are made.
Fortunately the phosphorus, turned from a curse into a blessing, develops by its oxidation the needed temperature, though the fact that this requires at least i.
The " pig and ore " or " Siemens " variety of the process works chiefly by oxidation, the " pig and scrap " or " Siemens-Martin " variety chiefly by dilution, sometimes indeed by extreme dilution, as when Io parts of cast iron are diluted with 90 parts of scrap. Both varieties may be carried out in the basic and dephosphorizing way, i.e.
The oxidation of the foreign elements must be very slow, lest the effervescence due to the escape of carbonic oxide from the carbon of the metal throw the charge out of the doors and ports of the furnace, which itself must be shallow in order to hold the flame down close to the charge.
The two metallic masses coalesce, and the reaction between the oxygen of one and the carbon of the other is therefore extremely rapid because it occurs throughout their depth, whereas in common procedure oxidation occurs only at the upper surface of the bath of cast iron at its contact with the overlying slag.
The oxygenated metal is prepared by melting cast iron diluted with as much scrap steel as is available, and oxidizing it with the flame and with iron ore as it lies in a thin molten layer, on the hearth of a large open-hearth furnace; the thinness of the layer hastens the oxidation, and the large size of the furnace permits considerable frothing.
At this time the slag is temporarily rich in iron oxide and silica, resulting from the oxidation of the iron and of its silicon as the charge slowly melts and trickles down.
In the basic open-hearth process, on the other hand, silicon is harmful because the silica which results from its oxidation not only corrodes the lining of the furnace but interferes with the removal of the phosphorus, an essential part of the process.
Next comes the deoxidizing and desulphurizing stage, of which the first step is to throw some strongly deoxidizing substance, such as coke or ferro-silicon, upon the molten metal, in order to remove thus the chief part of the oxygen which it has taken up during the oxidation of the phosphorus in the preceding stage.
Traube, Ber., 1882, 15, p. 659); in the oxidation of zinc, lead and copper in presence of water, and in the electrolysis of sulphuric acid of such strength that it contains two molecules of water to one molecule of sulphuric acid (M.
And so, as a rule, from isomeric alcohols, those containing a group - CH 2.0H, yield by oxidation aldehydes and are distinguished by the name primary; whereas those containing CH OH, called secondary, produce ketones.
This change of colour is chiefly occasioned by the diminished circulation in the leaves, and the higher degree of oxidation to which their chlorophyll has been submitted.
The next process is familiarly termed fermentation, but is really an oxidation of the leaves.
In this way as the water sinks down through the porous subsoil or into the subterranean drains oxygen enters and supplies an element which is needed, not only for the oxidation of organic matters in the earth, but also for the direct and indirect nutrition of the roots.
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.
It is found, more especially in the case of organic compounds, that if a substance which oxidizes readily at ordinary temperature be mixed with another which is not capable of such oxidation, then both are oxidized simultaneously, the amount of oxygen used being shared equally between them; or in some cases when the substance is spontaneously oxidized an equivalent amount of oxygen is converted into ozone or hydrogen peroxide.
The oxygen uniting with the substance undergoing oxidation is generally known as "bound oxygen," whilst that which is transformed into ozone or hydrogen peroxide is usually called "active oxygen."
Traube (loc. cit.), on the other hand, concludes that the oxygen molecule enters into action as a whole and that on the oxidation of metals, hydrogen peroxide and the oxide of the metal are the primary products of the reaction.
The hydrated form, found native as the mineral manganite, is produced by the spontaneous oxidation of manganous h y droxide.
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)].
On oxidation it gives triphenylcarbinol, (C 6 H 5) 3 C OH, and reduction with hydriodic acid and red phosphorus gives benzene and toluene.
In the massive state it is unacted upon by dry air, but if moistened with acidified water, oxidation takes place slowly.
By boiling this varnish with dilute nitric acid vapours of acrolein are given off, and the substance gradually becomes a solid non-adhesive mass the same as the ultimate oxidation product of both raw and boiled oil.
It may be prepared by the oxidation of fats and of fatty acids by nitric acid, and is also a product of the fermentation of malic and tartaric acids.
As a rule, wines which are kept for many years in cask become very dry, and the loss of alcohol by evaporation - particularly in the case of light wines - has as a result the production of acidity by oxidation.
This process indicates a very intensive form of oxidation inasmuch as no intermediary acid is formed.
In the process of oxidation, a certain amount of cuprous oxide is always formed, which melts in with the copper and diminishes its softness and tenacity.
The surface of the molten metal is protected from oxidation by a layer of anthracite or charcoal.
One of the earliest and most exhaustive series of experiments was made on Rio Tinto ores at the John Brown works by John Hollway, with the aim of both smelting the ore and concentrating the matte in the same furnace, by the heat evolved through the oxidation of their sulphur and iron.
The heat generated by the oxidation of iron and sulphur has always been used to maintain combustion in the kilns or stalls for roasting pyrites.
A portion of the white metal is calcined to such a degree of oxidation that when fused with the unroasted portion, the reaction between the oxygen in the roasted matte and the sulphur in the raw VII.
It may be prepared artificially by heating copper wire to a white heat, and afterwards at a red heat, by the atmospheric oxidation of copper reduced in hydrogen, or by the slow oxidation of the metal under water.
Its solution in ammonia is at first colourless, but rapidly turns blue, owing to oxidation.
Cooh, is obtained by the oxidation of milk, sugar, dulcite, galactose, quercite and most varieties of gum by nitric acid.
From considering the nature of diabetes, he had come to the conclusion that many cases were due to imperfect oxidation of sugar in the body; that this oxidation was normally carried out by a ferment in the muscles, and that probably the disease was in some cases dependent upon absence of the ferment.
After oxidation, the product is reduced by heating with carbon, care being taken to prevent any loss through volatilization, by covering the mass with a layer of some protective substance such as potash, soda or glauber salt, which also aids the refining.
As regards the ammonium carbonate accumulating in the soil from the conversion of urea and other sources, we know from Winogradsky's researches that it undergoes oxidation in two stages owing to the activity of the so-called " nitrifying " bacteria (an unfortunate term inasmuch as " nitrification " refers merely to a particular phase of the cycle of changes undergone by nitrogen).
It had long been known that under certain conditions large quantities of nitrate (saltpetre) are formed on exposed heaps of manure, &c., and it was supposed that direct oxidation of the ammonia, facilitated by the presence of porous bodies, brought this to pass.
The energy liberated during the oxidation of the nitrogen is regarded as splitting the carbon dioxide molecule, - in green plants it is the energy of the solar rays which does this.
The suggestion that it is due to the oxidation of a body excreted by the bacteria seems answered by the failure to filter off or extract any such body.
Beyerinck's view that it occurs at the moment peptones are worked up into the protoplasm cannot be regarded as proved, and the same must be said of the suggestion that the phosphorescence is due to the oxidation of phosphoretted hydrogen.
Promise of more light on these oxidation fermentations is afforded by the recent discovery that not only bacteria and fungi, but even the living cells of higher plants, contain peculiar enzymes which possess the remarkable property of " carrying " oxygen - much as it is carried in the sulphuric acid chamber - and which have therefore been termed oxydases.
The purple bacteria have thus two sources of energy, one by the oxidation of sulphur and another by the absorption of " dark rays."
The Royal Society's Catalogue enumerates 171 papers by him on various chemical topics, but his name is best known for his experiments on platinum in a minute state of division and on the oxidation products of alcohol.
So long as the solution contains a ferrous salt, the drop on the tile changes to blue; hence the absence of a blue coloration indicates the complete oxidation of all the ferrous salt and the end of the reaction.
Goldschmiedt (Monats., 1883-1889), who determined its constitution (formula I., below) by a study of its oxidation products, showing that papaveraldine, which it gives with potassium permanganate, is a tetramethoxybenzoylisoquinoline.
Roser (Ann., 1888, 249, p. 156; 1889, 2 54, p. 334.) By hydrolysis it yields opianic acid, C10H1005, and hydrocotarnine, C 12 1-1 15 NO 3; reduction gives meconine, C10H1004, and hydrocotarnine; whilst oxidation gives opianic acid and cotarnine, C12H15N04.
Potassium permanganate decomposes morphine by oxidation, the action being facilitated by the addition of a small quantity of mineral acid to the solution.
Reduction by sodium amalgam converts it into isopropyl alcohol; oxidation by chromic acid gives carbon dioxide and acetic acid.
Its salts, the selenates, are obtained by the oxidation of the selenites, and the free acid may be obtained by the decomposition of the lead or barium salt.
The cinchotannic acid apparently becomes altered by atmospheric oxidation into a red-colouring matter, known as cinchono-fulvic or cinchona red, which is very abundant in some species, as in C. succirubra.
Like alcohol and prussic acid, quinine interferes with oxidation, so that oxyhaemoglobin is relatively unable to give up its oxygen to the tissues, the metabolism of which is therefore greatly modified.
On oxidation with nitric acid the primary compounds give monoalkyl phosphinic acids, R PO(OH) 2r the secondary yielding dialkyl phosphinic acids, R 2 PO(OH).
Oxidation by potassium permanganate gives phthalic acid; whilst chromic acid gives carbon dioxide and water.
Metaor iso-xylene, the most important isomer, may be prepared by nucleus-synthetic reactions, or by distilling mesitylenic acid, C 6 H 3 (CH 3) 2 CO 2 H, an oxidation product of mesitylene, C 6 H 3 (CH 3) 3, which is produced on the condensation of acetone, with lime; this reaction is very important, for it orientates meta-compounds.
Cinchoninic acid (quinoline-y-carboxylic acid) is formed when cinchonine is oxidized by nitric acid, or by the oxidation of lepidine.
By oxidation with alkaline potassium permanganate it yields phthalic acid and cinchomeronic acid.
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 roasting of pyrites always takes place without using any extraneous fuel, the heat given off by the oxidation of the sulphur and the iron being quite sufficient to carry on the process.
The roasting of blende is nothing like so easy as that of pyrites, since the heat developed by the oxidation of the zinc sulphide itself is not sufficient for carrying on the process, and external heat must be applied.
Ergot should be kept in stoppered bottles in order to preserve it from the attacks of a species of mite, and to prevent the oxidation of its fatty oil.
Senderens, Comptes rendus, 1901, 132, p. 210 seq.); and from hydrazines of the type CnH2,2_1 NH NH2 by oxidation with alkaline potassium ferricyanide (N.
The a-acid on oxidation yields benzoic acid, whilst the 1 3-acid yields benzil in addition.
On oxidation it yields cyclo-pentane-pentanone (leuconic acid).
When reduced in alcoholic solution by means of sodium amalgam it yields methyl granatoline, 08H130H NCH3; this substance, on oxidation with cold potassium permanganate, is converted into granatoline, C 8 H, 5 NO, which on distillation over zinc dust yields pyridine.
The first two give origin to well-defined series of salts, the ferrous salts, wherein the metal is divalent, and the ferric salts, wherein the metal is trivalent; the former readily pass into the latter on oxidation, and the latter into the former on reduction.
Usually, however, it forms a greenish mass, owing to partial oxidation.
It occurs in nature as the mineral melanterite, either crystalline or fibrous, but usually massive; it appears to have been formed by the oxidation of pyrite or marcasite.
It is manufactured by piling pyrites in heaps and exposing to atmospheric oxidation, the ferrous sulphate thus formed being dissolved in water, and the solution run into tanks, where any sulphuric acid which may be formed is decomposed by adding scrap iron.
Ferrous sulphate and sodium carbonate in the cold give a flocculent precipitate, at first white but rapidly turning green owing to oxidation.
This doubtless prevented evaporation, and retarded vital processes dependent upon oxidation.
By gentle oxidation it yields nitrosobenzene.
On reduction it yields hexahydrotoluene; oxidation with dilute nitric acid or chromic acid gives benzoic acid; whilst chromyl chloride and water give benzaldehyde.
In the narrow sense "oxidation" may be regarded as the combination of a substance with oxygen, and conversely, "reduction" as the abstraction of oxygen; in the wider sense oxidation includes not merely the addition of oxygen, but also of other electro-negative elements or groups, or the removal of hydrogen or an electro-positive element or group. In inorganic chemistry oxidation is associated in many cases with an increase in the active valency.
Ignoring processes of oxidation or reduction simply brought about by heat or some other form of energy, we may regard an oxidizing agent as a substance having a strong affinity for electro-positive atoms or groups, and a reducing agent as having a strong affinity for electro-negative atoms or groups; in the actual processes the oxidizing agent suffers reduction and the reducing agent oxidation.
Many substances undergo simultaneous oxidation and reduction when treated in a particular manner; this is known as selfor auto-oxidation.
Of chief importance is their behaviour on oxidation.
The primary alcohols are first oxidized to aldehydes, which, on further oxidation, yield acids containing the same number of carbon atoms as in the original alcohol.
Oxidation by strong oxidizing agents converts it successively into its aldehyde, acrolein, and into acrylic acid.
By gentle oxidation with potassium permanganate it may be converted into glycerin.
Many complex derivatives are known, such, for example, as phosphor-vanadates, arsenio-vanadates, tungsto-vanadates, molybdovanadates, &c. For the use of this oxide in the electrolytic oxidation and reduction of organic compounds, see German Patents 172654 (1903) and 183022 (1905).
Oxidation gives naphthalic acid (1,8-naphthalene dicarboxylic acid).
Arsenic pentoxide, As2O5, is most easily obtained by oxidation of a solution of arsenious acid with nitric acid; the solution on concentration deposits the compound 2H3AsO4.
He also devised a method of great value in the quantitative analysis of organic substances for the estimation of nitrogen, while the classification, of organic compounds into homologous series was advanced as one consequence of his researches into the acids generated by the oxidation of the alcohols.
Oxidation of the ammoniacal solution gives orcein, C28H24N207, the chief constituent of the natural dye archil.
On oxidation by nitric acid they yield sulphonic acids.
The oxidation of aniline has been carefully investigated.
Formerly the process was regarded as oxidation pure and simple, and, although it was known that iron did not rust in dry air, yet no attempt was made to explain why water was necessary to the action.
The products of oxidation are not yet fully known; most likely they consist of lower fatty acids, such as formic and acetic acids, and perhaps also of aldehydes and ketones.
Inorganic bodies, such as metals, may enter into albuminous combinations which may greatly modify their effects, and organic substances may be split up into simpler compounds by oxidation or reduction, or may be rendered more complex by synthesis.
Others are rich in pyrites, which, on oxidation, produces sulphuric acid; this attacks the aluminous silicates of the clay and forms aluminium sulphate (alum shales).
This is generally done by making the bed of the furnace very long in proportion to its breadth and to the fire-grate area, which may be the more easily done as a not inconsiderable amount of heat is given out during the oxidation of the ore - such increased length being often obtained by placing two or even three working beds one above the other, and allowing the flame to pass over them in_order from below upwards.
In fact the only means of detoxification at this time was by oxidation with hypochlorite bleaches.
It is measured by the complete oxidation of the food in a bomb calorimeter.
Animals obtain their energy by oxidation of foods, plants do so by trapping the sunlight using chlorophyll.
The final precipitate contains cobalt in the +3 oxidation state.
Biotin (vitamin H) is an essential coenzyme that assists in the synthesis and oxidation of fatty acids.
Transmission line with exposed conductor surfaces can experience oxidation and an increase in losses due to skin effect heating.
Irbesartan is metabolized by the liver via glucuronide conjugation and oxidation.
The results obtained so far clearly indicate a synergistic effect between oxidation and alkali salt induced corrosion (the so-called hot corrosion ).
Oxidation of Alcohols Alcohols are oxidized by warming with an oxidizing agent, such as acidified potassium dichromate (VI) solution.
Subsequent acid oxidation of the type used on the original material again yielded an aqueous dispersion.
Control of fatty acid oxidation is exerted mainly at the step of fatty acid oxidation is exerted mainly at the step of fatty acid entry into mitochondria.
The two main reasons for iron gall ink corrosion have been identified to be acid hydrolysis and oxidation, catalyzed by ferrous ions.
We would suggest serving mead lightly chilled and whilst mead keeps well it should be kept cool and closed to reduce oxidation.
Molecular Ecology of Methane oxidation We have been developing molecular biology techniques to study the ecology of methane oxidation We have been developing molecular biology techniques to study the ecology of methane oxidizers.
The rocks of this period are characteristically red in color due to the oxidation of iron-rich minerals in the sediments under the arid conditions.
However other enzymes in living material can also catalyze oxidation with the oxygen in air.
Antioxidants inhibit the oxidation of lipids in cell membranes, leading to impairment of cell function.
State that catalytic oxidation can be carried out in the Laboratory.
We are also investigating anaerobic methane oxidation using conventional and molecular techniques.
Control of fatty acid oxidation is exerted mainly at the step of fatty acid entry into mitochondria.
Laboratory work will be complemented by both chamber and modeling studies, to provide improved mechanisms for aromatic oxidation.
This involves looking at catalytic dissociation of ammonia to hydrogen and nitrogen and also the selective catalytic oxidation of ammonia to nitrogen and water.
Many ways exist to produce hydrogen from fossil fuels, with partial oxidation being one of the most competitive.
Here we are trying to maintain a methane oxidation mechanism that is always up-to-date.
These results indicate similar behavior to that of lipid oxidation.
In both trials, total fat oxidation was higher and the total ingested carbohydrates oxidation lower in the boys than in the men.
X-ray photoelectron spectroscopy provides stronger evidence that the surface of these granules is modified by oxidation.
The nominal TiO in the X-ray photoelectron spectrum (XPS) upon which they rely heavily has almost certainly suffered surface oxidation.
The process must be carefully controlled to maintain complete oxidation but to minimize thermal NOx formation, which is itself, a pollutant.
You could eventually get back to the element vanadium which would have an oxidation state of zero.
There is information about cell chemistry, oxidation-reduction reactions, the copper zinc cell and further detail about oxidation states.
He showed that lead sulphide, a black substance containing only lead and sulphur, could be converted by oxidation into lead sulphate, a white compound containing oxygen as well as lead and sulphur.
In many parts, particularly in the eastern basin, a calcareous or siliceous crust, from half an inch to three inches in thickness, is met with; and Natterer suggested that the formation of this crust may be due to the production of carbonate of ammonium where deposits containing organic matter are undergoing oxidation, and the consequent precipitation of carbonate of lime and other substances from the waters nearer the surface.
They set up a process of oxidation in the substances which they attack, and have consequently been named oxidases.
The changes involve a continual liberation of energy, which in most cases is caused by the respiration of the protoplasm and the oxidation of the substances it contains.
Phys., 1888 (6) 14, p. 435); by heating phenol carboxylic acids with baryta; and, in small quantities by the oxidation of benzene with hydrogen peroxide or nascent ozone (A.
For succinosuccinic ester, formed by the action of sodium on two molecules of succinic ester, has either of the formulae (I) or (II); oxidation of the free acid gives dioxyterephthalic acid in which the para-positions must remain substituted as in (I) and (II).
Many organic compounds can be prepared by taking advantage of secondary actions at the electrodes, such as reduction by the cathodic hydrogen, or oxidation at the anode (see Electrochemistry).
The name is derived from alcohol dehydrogenatum in allusion to the fact that they may be prepared by the oxidation of alcohols.
Sandmeyer, Ber., 1887, 20, p. 1494) by the action of copper powder on the double salt formed by the addition of potassium mercuric nitrite to diazonium nitrites; and by the oxidation of primary aromatic amines (E.
In the dropsy of cardiac disease, owing to the deficient oxidation from stagnation of blood, metabolic products must accumulate in the tissues; also lymph return must be impeded by the increased pressure in the veins and so dropsy results (Wells).
This increased osmotic pressure is again due to accumulation of crystalloids in the tissues, either products of metabolism due to deficient oxidation from alteration in the blood or other cause, or, it may be, as in some cases of nephritis, owing to a.
Mannite on oxidation yields an aldose, mannose, C6H12061 which 3 To distinguish the isomerides of opposite optical activity, it is usual to prefix the letters d- and 1-, but these are used only to indicate the genetic relationship, and not the character of the optical activity; ordinary fructose, for example, being represented as d-fructosealthough it exercises a laevorotatory power - because it is derived from d-glucose.
The further oxidation of the nitrite to a nitrate is effected by bacteria belonging to the genus Nitrobacter.
If hot air is introduced into the kiln, the additional heat developed by the oxidation of the zinc and the sulphur is sufficient to keep up a part of the reaction; but for the complete expulsion of the sulphur an externally-fired muffle through which the ore is passed is found to be essential.
The numerical relations existing between the trunk series and the branch series make it somewhat difficult to believe that they belong to different vibrating systems. But while we should undoubtedly hesitate on this ground to adopt Fredenhagen's 3 view that the two branch series belong to the element itself and the trunk series to a process of oxidation, we cannot press the argument against the view of Lenard, because the addition or subtraction of an electron introduces two vibrating systems which are still connected with each other and some numerical relationship is probable.
Bamberger, Ber., 1893.26, p. 49 6); by the oxidation of nitrosobenzene (below) with atmospheric oxygen; or by the decomposition of benzene diazonium nitrate mercury nitrite, Hg(NO 2) 2.2C 6 H 5 N 2 NO 3, with copper powder (A.
Cupric sulphate is obtained commercially by the I 91,000 96,000 1 35, 000 218,400 291,000 900,000 oxidation of sulphuretted copper ores (see above, Metallurgy; wet methods), or by dissolving cupric oxide in sulphuric acid.
Vitamin E is an antioxidant which can help keep you looking younger by retarding cellular aging due to oxidation.
Iron compounds, in various states of oxidation and reduction (hydration) are major coloring agents of subsoil horizons.
Green Tea - made from tea leaves that are minimally processed and go through less oxidation that other teas.
Once this oxidation process starts, what's left is converted into water, carbon dioxide and biomass.
The CMP in cocoa butter is further believed to inhibit the growth of cancerous cells and tumors by reducing active oxygen levels, inhibiting the oxidation of LDL (good cholesterol) and inhibiting the production of inflammatory cells.
To see oxidation in action, cut an apple or a potato and watch as it turns brown.
They diminish the oxidation process that can occur within cells, removing harmful free radicals.
If you place one in an area that's exposed to high humidity, it will resist oxidation, and if it's located in a kitchen or smoking room, it won't discolor and can easily be cleaned with vinegar or a damp cloth.
Two sided adapters that will help make copper, galvanized and PVC configurations work together will make your life easier as long as you don't run into other problems, like major oxidation.
Timberwolf's dry food is protected by an oxygen barrier designed to prevent oxidation.
These free radicals are the result of oxidation in the body.
Oxidation, an important process in black tea, is omitted or greatly reduced.
This ensures that the clean, crisp flavor of the white wine is protected from too much oxidation, which can mask the delicate flavors of the white wines.
The rim is a bit more openly, allowing oxidation and full development of the wine.
Constant shifting and movement disturbs the natural settling process in the wine and may lead to oxidation.
Once you open a bottle, oxidation begins, causing degradation of the wine.
A good wine rack stores wine on its side in order to keep the cork moist and prevent oxidation of the wine.
Once the bottle is opened, there is nothing that can be done to completely stop this oxidation process.
Oxidation can, however, be slowed by using wine stoppers.
If you plan to keep a bottle of wine more than a week or two, then the wine needs ideal conditions so that it ages without oxidation.
Because wine can be so temperamental in long-term storage situations, a wine cooling system can eliminate much of the worry about oxidation and can help you to age your investment properly.
The bag within a box construction prevents oxidation, which typically occurs when you pour wine from the bottle, allowing air to enter.
Consider investing in a wine stopper that vacuums the air out, which will prevent oxidation for a longer period.
Box wine isn't prone to wine spoilage issues such as mercaptan, oxidation and cork taint.
Commonly found in tea, chocolate, cheese, and nuts, tannins are flavonoid-producing chemicals that prevent the oxidation of wine.
Methemoglobin-A compound formed from hemoglobin by oxidation of its iron component.
Vitamin E - maintains integrity of cell membranes throughout the body and protects fats in low density lipoproteins from oxidation.
Vitamin E is well known for its importance as an antioxidant and its ability to protect our body tissue from oxidation.
Referred to as oxidation, rancid fish oils lead to lipid peroxides, which "can (and do) start free radical cascades that can damage fatty cellular membranes," according to Dr. Eades.
Some evidence seems to indicate that it may not be LDL that causes artherosclerosis, but rather the oxidation of that LDL. Enter CoQ10.
It causes less oxidation of the nutrients while providing more juice from produce than the other types of juicers.
Oxygen, while essential to living, also causes oxidation, which is a natural decaying process of animal tissue.
Topical and oral use of antioxidants support healthy skin and hair by fighting the oxidation that results from free-radicals.
Oxidation causes much of the damage that occurs to skin as you age.
However, all of these handbags will be old, and Bakelite items that were manufactured in the early 1900s are subject to the oxidation discoloration inherent to Bakelite.
If you find internal defects, such as oxidation, scratches, or hazing, remove these successfully with any combination of rubbing/buffing compounds, paint cleaners, and/or essential paint oils.
Oxidation leaves a coin dull but all the soap in the world won't bring back the shine.
Plenty of antioxidant rich veggies and fruits - the theory behind this is that some of the body damage sustained by people with diabetes; such as eye, skin, and nerve damage may be the cause of oxidation present with glucose elevation.
Even if your old cast iron skillet has a bit of oxidation, don't throw it away--it isn't too hard to remove rust from cast iron skillets.
Toluene also inhibits oxidation, which means that nail polish won't stick to the nails.
Decreases in retinol levels cause the oxidation of unsaturated fatty acids in the cell, which causes toxic effects.
Vitamin E curbs this oxidation process and restores normal levels of retinol.
Kinetin is found naturally in leafy green plants, and is also produced by the human body as a protective response to oxidation.
On oxidation with potassium permanganate it is converted into acetyl urea, together with other products.
The urine becomes dark green in colour owing to the formation of various oxidation products such as pyrocatechin.
Strong oxidation breaks the benzene complex into such compounds, as carbon dioxide, oxalic acid, formic acid, &c.; such decompositions are of little interest.
The furnace has, in addition to the usual tuyeres near the bottom, a second set near the throat in order to effect a complete oxidation of all combustible matter.
As a matter of fact, only arabinose gives an active product on oxidation; it is therefore to be supposed that arabinose is the - - - compound, and consequently CH 2 (OH) - - - + COH = /-glucose CH 2 (OH) + - - - COH = l-gulose.
Even their oxidation, however, is effected by the protoplasm acting as an oxygen carrier.
As in Hopkinson's experiments, ring magnets were employed; these were wound with primary and secondary coils of insulated platinum wire, which would bear a much higher temperature than copper without oxidation or fusion.
Nitrosohydrocarbons have been prepared in the aliphatic series by the oxidation of the corresponding hydroxylamino compounds.
It is obtained by the oxidation of orthophenylene diamine with ferric chloride; when a mixture of para-aminodimethylaniline and meta-toluylenediamine is oxidized in the cold, toluylene blue, an indamine, being formed as an intermediate product and passing into the red when boiled; and also by the oxidation of dimethylparaphenylene diamine with metatoluylene diamine.
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.
The whole was wrapped in several coverings of asbestos and placed in a glass vessel from which the air was partially exhausted, additional precautions being taken to guard against oxidation of the iron.
It is reduced by nascent hydrogen to the secondary alcohol C6H5.CH.OH.CH3 phenyl-methyl-carbinol, and on oxidation forms benzoic acid.