Acids common

Sulphur can be reduced directly to hydrogen sulphide by passing hydrogen through molten sulphur the reversible reaction H2 -I-S H2S occurs. In the laboratory the gas is most conveniently prepared by the action of an acid on a metal sulphide, iron(II) and dilute hydrochloric acid commonly being used ... [Pg.282]

These are acids which can be regarded, in respect of their formulae (but not their properties) as hydrates of the hypothetical diiodine heptoxide, liO-j. The acid commonly called periodic acid , I2O7. 5H2O, is written HglO (since the acid is pentabasic) and should strictly be called hexaoxoiodic(VII) acid. It is a weak acid and its salts are hydrolysed in solution. It can be prepared by electrolytic oxidation of iodic(V) acid at low temperatures ... [Pg.342]

This table lists the and pi (pH at the isoelectric point) values of a-amino acids commonly found in proteins along with their abbreviations. The dissociation constants refer to aqueous solutions at 25°C. [Pg.1179]

Alkyl esters of trifluoromethanesulfonic acid, commonly called triflates, have been prepared from the silver salt and an alkyl iodide, or by reaction of the anhydride with an alcohol (18,20,21). Triflates of the 1,1-dihydroperfluoroalkanols, CF2S020CH2R can be prepared by the reaction of perfluoromethanesulfonyl fluoride with the dihydroalcohol in the presence of triethylamine (22,23). Triflates are important intermediates in synthetic chemistry. They are among the best leaving groups known, so they are commonly employed in anionic displacement reactions. [Pg.315]

Salts of acids other than hydrochloric acid commonly show increased solubiUty in hydrochloric acid. This phenomenon has been explained by the Debye-Hbckel theory for strong electrolytes (17—19). [Pg.442]

In addition to the conventional mixed acids commonly used to produce DNT, a mixture of NO2 and H2SO4 (8), a mixture of NO2 and oxygen (9), and just HNO (10) can also be used. TerephthaUc acid and certain substituted aromatics are more amenable to nitrations using HNO, as compared to those using mixed acids. For compounds that are easily nitratable, acetic acid and acetic anhydride are sometimes added to nitric acid (qv). Acetyl nitrate, which is a nitrating agent, is produced as an intermediate as follows ... [Pg.33]

The potassium or calcium salt form of oxaUc acid is distributed widely ia the plant kingdom. Its name is derived from the Greek o>ys, meaning sharp or acidic, referring to the acidity common ia the foflage of certain plants (notably Oxalis and Mmex) from which it was first isolated. Other plants ia which oxahc acid is found are spinach, rhubarb, etc. Oxahc acid is a product of metabohsm of fungi or bacteria and also occurs ia human and animal urine the calcium salt is a principal constituent of kidney stones. [Pg.455]

Mineral acids are used as catalysts, usually in a concentration of 20— 40 wt % and temperatures of 30—60°C. An efficient surfactant, preferably one that is soluble in the acid-phase upon completion of the reaction, is needed to emulsify the a-pinene and acid. The surfactant can then be recycled with the acid. Phosphoric acid is the acid commonly used in the pine oil process. Its mild corrosion characteristics and its moderate strength make it more manageable, especially because the acid concentration is constandy changing in the process by the consumption of water. Phosphoric acid is also mild enough to prevent any significant dehydration of the alcohols formed in the process. Optimization of a process usually involves considerations of acid type and concentration, temperature, surfactant type and amount, and reaction time. The optimum process usually gives a maximum of alcohols with the minimum amount of hydrocarbons and cineoles. [Pg.420]

Branched-chain acid (common name) CAS Registry Number Molecular weight Boiling point, °C Melting point, °C Approximate price, [kR Producers in the United States... [Pg.100]

Ascorbic acid commonly known as vitamin C, is one of the most important water soluble vitamins. Ascorbic acid is involved in many biological processes and it is an essential compound in the human diet [1]. The determination of ascorbic acid has gained increase significance in pharmaceutic, clinical, and food applications. So far, different methods have been developed for determination of ascorbic acid [2, 3]. [Pg.154]

Accelerated sulphur systems also require the use of an activator comprising a metal oxide, usually zinc oxide, and a fatty acid, commonly stearic acid. For some purposes, for example where a high degree of transparency is required, the activator may be a fatty acid salt such as zinc stearate. Thus a basic curing system has four components sulphur vulcanising agent, accelerator (sometimes combinations of accelerators), metal oxide and fatty acid. In addition, in order to improve the resistance to scorching, a prevulcanisation inhibitor such as A -cyclohexylthiophthalimide may be incorporated without adverse effects on either cure rate or physical properties. [Pg.283]

Histidine is one of the 20 naturally occurring amino acids commonly found in proteins (see Chapter 4). It possesses as part of its structure an imidazole group, a five-membered heterocyclic ring possessing two nitrogen atoms. The pAl for dissociation of the imidazole hydrogen of histidine is 6.04. [Pg.51]

The structures and abbreviations for the 20 amino acids commonly found in proteins are shown in Figure 4.3. All the amino acids except proline have both free a-amino and free a-carboxyl groups (Figure 4.1). There are several ways to classify the common amino acids. The most useful of these classifications is based on the polarity of the side chains. Thus, the structures shown in Figure 4.3 are grouped into the following categories (I) nonpolar or hydrophobic... [Pg.82]

FIGURE 4.1 Anatomy of an amino acid. Except for proline and its derivatives, all of the amino acids commonly found in proteins possess this type of structure. [Pg.82]

Organic acids usually contain a carboxylic acid group, -CO2H. L-Ascorbic acid, commonly known as Vitamin C, is an obvious exception. [Pg.220]

When heated at or about their melting points cyclic hydroxamic acids commonly decompose to give the corresponding lactams. Thus,... [Pg.226]

Chemical Name 1-(p-Chloroben2oyl)-6-methoxy-2-methylindole-3-acetoxyacetic acid Common Name -... [Pg.9]

Therapeutic Function Antiinflammatory Chemical Name 3-Chloro-4-(2-propenyloxy)benzene-acetlc acid Common Name [4-(allyloxy)-3-chlorophenyl] acetic acid Structural Formula Cl... [Pg.33]

Therapeutic Function Sunscreen agent, antirickettsial Chemical Name p-aminobenzolc acid Common Name Vitamin H, Vitamin B, PABA Structural Formula ... [Pg.62]

Chemical Name 6-aminohexanoic acid Common Name Epsilcapramin Structural Formula HjNICHjljCOOH... [Pg.64]

Chemical Name 4-amino-2-hydroxybenzoic acid Common Name —... [Pg.68]

Chemical Name 3 chloro-4-cyclohexyl-a-oxo-ben2enebutanoic acid Common Name 4-(4 cvclohexvl-3-chlorophenyl)-4 oxobutyric acid Structural Formula ... [Pg.192]

Therapeutic Function Solubilizer for cholesterol gallstones Chemical Name 3,7-Dihydroxycholan-24-oic acid Common Name Chenodeoxycholic acid chenic acid Structural Formula ... [Pg.293]

Chamical Name 2-[4-(2, 2 -Dichlorocyclopropyl)phenoxy] -2-methylpropionic acid Common Name —... [Pg.346]

Chemical Name 2 -[Cyclohexylidenebis(4,1 -phenyleneoxy)] bis[2-methylbutanoic acid] Common Name —... [Pg.359]

Therapeutic Function Diagnostic aid (radiopaque medium) Chemical Name 3,5-6is(acetylamino)-2,4,6-trliodobenzo c acid Common Name Amidotrizoate sodium... [Pg.462]

Chemical Name 1 -(3-Cyano-3,3-diphenylpropyI)-4-phenyl-4-piperidinecarboxylie acid Common Name Difenoxillc acid... [Pg.485]

Chemical Name 2, 4 -Difluoro4-hydroxy-[ 1,1 -biphenyl] -3<arboxylic acid Common Name Difluorophenyl salicylic acid Structural Formula cooh... [Pg.489]

Therapeutic Function Oxytocic abortifacient Chemical Name 11,15-Dihydroxy-9-oxoprosta-5,13-dien-1-oic acid Common Name Prostaglandin E2, PGE2 Structural Formula o... [Pg.509]

Therapeutic Function Analgesic, antipyretic and antiinflammatory Chemical Name 4-(p-Chlorophenyl)-2-phenyl-thiazol-5-yl-acetic acid Common Name —... [Pg.634]

Therapeutic Function Hydrocholeretic Chemical Name 7-Oxo-8-fluoranthenebutanoic acid Common Name -Structural Formula ... [Pg.647]

Chemical Name 5-(aminosulfonvl)-4-chloro-2-[(2-furanylmethvl)amino] benzoic acid Common Name —... [Pg.709]

Chemical Name 0 -methyl-4-(2-methylpropyl)ben2ene acetic acid Common Name 2-(4-isobutylphenyl)propionic acid... [Pg.796]

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