In the presence of water, sulfur trioxide ( SO < sub > 3 </ sub >) is converted rapidly to sulfuric acid:

DDT does not occur naturally, but is produced by the reaction of chloral () with chlorobenzene () in the presence of sulfuric acid, which acts as a catalyst.

Using argon bubbles in sulfuric acid, their data show the presence of ionized molecular oxygen O < sub > 2 </ sub >< sup >+</ sup >, sulfur monoxide, and atomic argon populating high-energy excited states, which confirms a hypothesis that the bubbles have a hot plasma core.

in the presence of a dehydrating agent, such as concentrated sulfuric acid.

In the presence of oxygen ( aerobic ), some bacteria may directly oxidize iron to iron oxides and hydroxides, other bacteria oxidize sulfur and produce sulfuric acid causing biogenic sulfide corrosion.

It is important to note that at higher temperatures and the presence of phosphoric acid, the corrosion rates increase while sulfuric acid helped the corrosion rates and kept the substances from corrosion.

In a standard oil refinery process, isobutane is alkylated with low-molecular-weight alkenes ( primarily a mixture of propene and butene ) in the presence of a strong acid catalyst, either sulfuric acid or hydrofluoric acid.

The cellulose is then reacted with acetic acid and acetic anhydride in the presence of sulfuric acid.

Molisch's test ( named after Austrian botanist Hans Molisch ) is a sensitive chemical test for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid to produce an aldehyde, which condenses with two molecules of phenol ( usually α-naphthol, though other phenols ( e. g. resorcinol, thymol ) also give colored products ), resulting in a red-or purple-colored compound.

Pentyl butyrate, also known as pentyl butanoate or amyl butyrate, is an ester that is formed when pentanol is reacted with butyric acid, usually in the presence of sulfuric acid as a catalyst.

With concentrated nitric acid, in the presence of cold concentrated sulfuric acid, it yields trinitro-resorcin ( styphnic acid ), which forms yellow crystals, exploding violently on rapid heating.

Nitrogen oxides are produced by decomposition of niter in the presence of sulfuric acid or hydrolysis of nitrosylsulfuric acid:

Cellulose reacts with carbon disulfide ( CS < sub > 2 </ sub >) in presence of sodium hydroxide ( NaOH ) to produces sodium cellulose xanthate, which upon neutralization with sulfuric acid ( H < sub > 2 </ sub > SO < sub > 4 </ sub >) gives viscose rayon or cellophane paper ( Sellotape or Scotch Tape ).

Some species are partially acid fast ( meaning that a less concentrated solution of sulfuric or hydrochloric acid should be used during the staining procedure ) due to the presence of intermediate-length mycolic acids in their cell wall.

It can be formed by reaction of butanol with concentrated hydrobromic acid in presence of strong acid, such as sulfuric acid ( H < sub > 2 </ sub > SO < sub > 4 </ sub >), by reaction of dibutyl ether with hydrobromic acid, or bromination of butane in presence of peroxide.

The reaction mechanism is unclear, yet there is good reason to believe that acrolein ( obtained by dehydration of glycerol in presence of concentrated sulfuric acid ) is an intermediate, which then undergoes 1, 4-addition.

* Other apomorphic characters of the order according to Stevens are: the presence of chelidonic acid, anthers longer than wide, tapetal cells bi-to tetra-nuclear, tegmen not persistent, endosperm helobial, and loss of mitochondrial gene sdh3.

There are numerous qualitative chemical tests, for example, the acid test for gold and the Kastle-Meyer test for the presence of blood.

The Arrhenius definition of acid – base reactions is a development of the hydrogen theory of acids, devised by Svante Arrhenius, which was used to provide a modern definition of acids and bases that followed from his work with Friedrich Wilhelm Ostwald in establishing the presence of ions in aqueous solution in 1884, and led to Arrhenius receiving the Nobel Prize in Chemistry in 1903 for " recognition of the extraordinary services ... rendered to the advancement of chemistry by his electrolytic theory of dissociation ".

Further separation was carried out in the presence of a citric acid / ammonium buffer solution in a weakly acidic medium ( pH ≈ 3. 5 ), using ion exchange at elevated temperature.

In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion,.

This equilibrium between carbonate, bicarbonate, carbon dioxide and carbonic acid in water can, under changing temperature or pressure conditions, and in the presence of metal ions with insoluble carbonates, result in formation of insoluble compounds.

An autumn 2004 caution from the Committee on Safety of Medicines, the UK agency dealing with drug safety, advised patients taking warfarin not to drink cranberry juice after adverse effects ( such as increased incidence of bruising ) were reported, possibly resulting from the presence of salicylic acid native to polyphenol-rich plants such as the cranberry.

Larger amounts of radioactive material were later isolated from coral debris of the atoll, which were delivered to the U. S. The separation of suspected new elements was carried out in the presence of a citric acid / ammonium buffer solution in a weakly acidic medium ( pH ≈ 3. 5 ), using ion exchange at elevated temperatures ; fewer than 200 atoms of einsteinium were recovered in the end.

The classic synthesis is the Fischer esterification, which involves treating a carboxylic acid with an alcohol in the presence of a dehydrating agent:

Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to confirm the presence of gold in items, giving rise to the term the acid test.

Another common variation was to distil in the presence of sulphuric acid.

Phenylacetic acid in the presence of a base will lose water to produce phenylketene due to the high acidity of the alpha proton.

Nucleic acids were named for their initial discovery within the nucleus, and for the presence of phosphate groups ( related to phosphoric acid ).

Nucleic acid types differ in the structure of the sugar in their nucleotides-DNA contains 2 '- deoxyribose while RNA contains ribose ( where the only difference is the presence of a hydroxyl group ).

PRPP transferase catalyzes both the ribosylation and decarboxylation reactions, forming UMP from orotic acid in the presence of PRPP.

Prominent examples include the reaction of nitric acid and cellulose to form nitrocellulose and the formation of vulcanized rubber by heating natural rubber in the presence of sulfur.

One way to do this, which has been used extensively, is to titrate a solution of known concentration of a strong acid with a solution of known concentration of strong alkali in the presence of a relatively high concentration of background electrolyte.

They were able to form protein-like chains from a mixture of 18 common amino acids at only 70 ° C in the presence of phosphoric acid, and dubbed these protein-like chains proteinoids.

Silver fulminate (), a powerful, touch-sensitive explosive used in percussion caps, is made by reaction of silver metal with nitric acid in the presence of ethanol ().

Some fruits and vegetables not high in vitamin C may be pickled in lemon juice, which is high in vitamin C. Though redundant in the presence of a balanced diet, various nutritional supplements are available that provide ascorbic acid well in excess of that required to prevent scurvy, and even some candies and most soft drinks contain vitamin C as a preservative.

In the presence of phosphate anions, Th < sup > 4 +</ sup > forms precipitates of various compositions, which are insoluble in water and acid solutions.

Thus in strong alkali at high pH, it forms the dually charged full urate ion, but at biological pH or in the presence of carbonic acid or carbonate ions, it forms the singly charged hydrogen or acid urate ion as its pKa < sub > 1 </ sub > is lower than the pKa < sub > 1 </ sub > of carbonic acid.

The reaction is carried out under pressure at a temperature of 200 ° C in the presence of a metallic catalyst.

The decoloration of a solution of bromine in water with dichloromethylene as catalyst is an analytical test for the presence of alkenes:

The steam cracking of alkanes affords a few percent acetylene, which is selectively hydrogenated in the presence of a palladium / silver catalyst.

The presence of the catalyst opens a different reaction pathway ( shown in red ) with a lower activation energy.

* The presence or absence of a catalyst.

The presence of a catalyst opens a different reaction pathway ( in red ) with a lower activation energy.

It is oxidized ( in a sense " burnt ") by heating with oxygen in the presence of a catalyst such as platinum with 10 % rhodium, to form nitric oxide and water.

Nitrogen fertilizers are often made using the Haber-Bosch process ( invented about 1915 ) which uses natural gas ( CH < sub > 4 +)</ sub > for the hydrogen and nitrogen gas ( N < sub > 2 </ sub >) from the air at an elevated temperature and pressure in the presence of a catalyst to form ammonia ( NH < sub > 3 </ sub >) as the end product.

This combining process, sometimes called condensation, typically requires the presence of a catalyst.

Foss's presence, and his knowledge, ability, enthusiasm, and imagination may well have been the catalyst bringing hitherto unconnected activities together in Milford's mind, as another new venture similar to the establishment of the overseas branches.

More recently he and Jessop have developed an industrial process for the manufacture of N, N-dimethylformamide from hydrogen, dimethylamine and supercritical carbon dioxide in the presence of < sub > 2 </ sub >( PMe < sub > 3 </ sub >)< sub > 4 </ sub > as catalyst.

Such reactions are usually conducted in the presence of an acid catalyst or UV light.

Only 5-10 mol % of the catalyst in the presence of 3Å molecular sieves ( 3Å MS ) is necessary.

This reaction is very slow in the absence of a catalyst, but quite fast in the presence of the hydroxide ion

The hydrogenation process involves " sparging " the oil at high temperature and pressure with hydrogen in the presence of a catalyst, typically a powdered nickel compound.

Commonly, the natural oils are hydrogenated by passing hydrogen through the oil in the presence of a nickel catalyst, under controlled conditions.

Hydrogenation-to treat with hydrogen-is a chemical reaction between molecular hydrogen ( H < sub > 2 </ sub >) and another compound or element, usually in the presence of a catalyst.

* A catalyst: The presence of a catalyst increases the reaction rate ( in both the forward and reverse reactions ) by providing an alternative pathway with a lower activation energy.

Turtledove approaches the novels ' science fiction scenario with less of a focus on the technological and fantasy elements typically associated with the genre and shows greater concern for the role of more mundane affairs such as the political repercussions of an alliance between the Allied and Axis powers, the impact the presence of alien creatures has on human society, and the ways in which warfare is paradoxically a hindrance to civilization and simultaneously a catalyst for the progress of civilization.

The reactions included in the calculation are only those that actually occur under the given conditions, and not those that might occur under different conditions such as higher temperature or the presence of a catalyst.

For example, if is luminol and is hydrogen peroxide in the presence of a suitable catalyst we have:

A somewhat smaller amount of 1, 1, 1-trichloroethane is produced from the reaction of vinylidene chloride and hydrogen chloride in the presence of an iron ( III ) chloride catalyst: