noun
definition
The combination of a substance with oxygen.
definition
A reaction in which the atoms of an element lose electrons and the oxidation state of the element increases.
Examples of 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.
It is very hygroscopic, dissolves readily in water, and rapidly undergoes oxidation on exposure to air.
The transformation is not one of the oxidation of a hexamethylene compound to a benzenoid compound, for only two hydrogen atoms are removed.
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 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.
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.
Methods depending upon oxidation in the presence of a contact substance have come into favour during recent years.
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.
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.
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.
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.
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."
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.
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.
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.