Synthetic empirical formulae

The known uranium(VI) carbonate soHds have empirical formulas, 1102(003), M2U02(C03)2, and M4U02(C03)3. The soHd of composition 1102(003) is a well-known mineral, mtherfordine, and its stmcture has been determined from crystals of both the natural mineral and synthetic samples. Rutherfordine is a layered soHd in which the local coordination environment of the uranyl ion consists of a hexagonal bipyramidal arrangement of oxygen atoms with the uranyl units perpendicular to the orthorhombic plane. Each uranium atom forms six equatorial bonds with the oxygen atoms of four carbonate ligands, two in a bidentate manner and two in a monodentate manner. 

Under the mineralogical name zeolite such sieves occur naturally. For technical purposes due to their higher uniformity only synthetic zeolites are used [10], In the empirical formula Me is an exchangeable cation of the valence n (zeolites are cation exchangers). Molecular sieves have a very regular and orderly crystal structure, which is characterized by a three-dimensional system of cavities with a diameter of 11 A. These cavities are interconnected by pores with a constant diameter. The value of this diameter depends on the type of the exchangeable cation Me. It is 5 A, if in the above formula Me stands for 75% Na+ and 25% Ca2+. 

Polychlorinated biphenyls (PCBs) are a group of 209 discrete synthetic chemical compounds, called congeners, in which one to ten chlorine atoms are attached to a biphenyl. The empirical formula for PCB is thus Ci2Hio nCln, where n is one to ten. The 209 congeners are systematically numbered from one to 209. 

Sermorelin acetate is the acetate salt of an amidated synthetic 29-amino acid peptide (GRF 1 -29 NH2) consisting of 44 amino acid residues. The free base of sermorelin has the empirical formula C 149 H 246 N 44 O 42 S and a MW of 3358 Da. 

Cermets (for cenmic plus mel are synthetic substances with both ceramic and metallic components. They combine the strength and toughness of metal with the resistance to heat and oxidation that ceramics offer. One cermet containing molybdenum and silicon was used to coat molybdenum engine parts on space vehicles. A sample of this compound is analyzed and found to contain 14.212 g of molybdenum and 8.321 g of silicon. WTiat is the empirical formula for this compound ... 

Calcipotriene cream, 0.005%, contains calcipotriene monohydrate, a synthetic vitamin D 3 derivative, for topical dermatological use. Chemically, calcipotriene monohydrate is (5Z,7E,22E,24S)-24-cyclopropyl-9,10-seco-chola-5,7,10(19), 22-tetraene-l(alpha),3(beta),24-triol monohydrate, with the empirical formula C27 H40 03 ... 

Mometasone furoate is a synthetic corticosteroid with anti-inflammatory activity. Chemically, mometasone furoate is 9a, 21-dichloro-lip,17-dihydroxy-16a-methyl-pregna-l,4-diene-3,20-dione-(2-furoate), with the empirical formula C27H30Cl2O6 and a molecular weight of 521.4. Mometasone furoate is a white to off-white powder practically insoluble in water, slightly soluble in octanol, and moderately soluble in ethyl alcohol. 

The cream 1% contains the synthetic, broad-spectrum, antifungal agent naftifine hydrochloride. It is for topical use only. The chemical name is (E)-N-Cinnamyl-N-methyl-l-naphthalenemethyl-amine hydrochloride. Naftifine hydrochloride has an empirical formula of C21H21N HC1 and a molecular weight of 323.86. The active ingredient... 

Prednicarbate emollient cream 0.1% contains prednicarbate, a synthetic corticosteroid for topical dermatologic use. The chemical name of prednicarbate is 11 (beta), 17,21-trihydroxypregna-l,4-diene-3,20-dione 17-(ethyl carbonate) 21-propionate. Prednicarbate has the empirical formula C27H3608 and a molecular weight of 488.58. Topical corticosteroids constitute a class of primarily synthetic steroids... 

Isobutylene is a hydrocarbon used in the manufacture of synthetic rubber. When 0.847 g of isobutylene was analyzed by combustion (using an apparatus similar to that in Figure 3.5), the gain in mass of the CO2 absorber was 2.657 g and that of the H2O absorber was 1.089 g. What is the empirical formula of isobutylene ... 

A chemical synthesis of a target molecule could be described in terms of the empirical formulas of the starting materials and some representative intermediates which are characteristic of the conversion of the starting materials into the synthetic target. Such a description would, however, be useless for most synthetic purposes, because it would be representative of a too-large equivalence class of syntheses. Perkins attempt to synthetize quinine from aniline, which led to the discovery of the triphenyl methane dyes, is a well documented example for the need of defining and representing equivalence classes of syntheses in a more detailed manner than by some characteristic empirical formulas. 

Cellulose-based plastics, particularly cellulose nitrate and acetates, were the most commercially important semi-synthetics up to the 1940s and were used as the base for photographic film, textile fibres, moulded goods and in lacquers. Naturally occurring polymer cellulose in the form of cotton linters or wood pulp is chemically treated to increase its solubility. Cellulose has a high molecular weight of between 100000 and 500000 and an empirical formula C0H1OO5. Casein-formaldehyde is the only protein-based moulded plastic that achieved commercial success. It is based on cow s milk and is still produced in very small quantities for specialist items such as hand-coloured buttons. 

Synthetic chemistry TOF-MS (API) flow injection analysis Accurate mass measurement for empirical formula determination... 

Synonyms Cumaldehyde Cumic aldehyde p-Cumic aldehyde Cuminal Cuminic aldehyde p-Cuminic aldehyde 4-lsopropylbenzaldehyde p-lsopropylbenzaldehyde p-Isopropylbenzenecarboxaldehyde 4-(1-Methylethyl) benzaldehyde Definition Constituent of eucalyptus, myrrh, cassia, cumin, and other essential oils or prepared synthetically Empirical C10H12O Formula (CH3)2CHC6H4CHO Properties Colorless to yish. oily liq., strong persistent aromatic odor, acrid burning taste sol. in alcohol, ether, toluene, oxygenated soivs. ... 

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