Formulae primes

Chemical Designations - Synonyms Kettle-rendered lard Leaf lard Prime steam lard Chemical Formula Not applicable. 

In 1929 Carothers proposed a generally useful differentiation between two broad classes of polymers condensation polymers in which the molecular formula of the structural unit (or units) lacks certain atoms present in the monomer from which it is formed, or to which it may be degraded by chemical means, and addition polymers, in which the molecular formula of the structural unit (or units) is identical with that of the monomer from which the polymer is derived. Condensation polymers may be formed from monomers bearing two or more reactive groups of such a character that they may condense intermolecu-larly with the elimination of a by-product, often water. The polyamides and polyesters referred to above afford prime examples of condensation polymers. The formation of a polyester from a suitable hydroxy acid takes place as follows ... 

To assure consistency and speed in multidisciplinary structure analysis of low-MW compounds involving various techniques (IR, NMR, MS, etc.) most industrial laboratories use a Standard Operating Procedure (SOP). In such schemes IR analysis is frequently used as a cheap filter for a quick starting control and as a means for verification. As IR detects only structural units identification of an unknown compound on the basis of IR is difficult. Mass spectrometry is used as the prime identification tool and is especially important in the determination of the exact mass and gross formulae. While structural prognostication on the basis of MS is difficult for the non-expert, a posteriori interpretation is quite feasible. H NMR is both easy and cheap, however requires greater sample quantities than either... 

In most cases, ointments, suppositories, ophthalmic, and parenteral products assume the color of their ingredients and do not contain color additives. In addition to esthetics and the certification status of a dye, a formulation pharmacist must select the dyes to be used in a particular formula on the basis of the physical and chemical properties of the dyes available. Of prime importance is the solubility of a prospective dye in the vehicle to be used for a liquid formulation or in a solvent to be employed during a pharmaceutical process (such as when the dye is sprayed on a batch of tablets). In general, most dyes are broadly grouped into those that are water-soluble and those that are oil-soluble few, if any, dyes are both. 

The molecular weight of a polymer is of prime importance in the polymer s synthesis and application. Chemists usually use the term molecular weight to describe the size of a molecule. The more accurate term is molar mass, usually in units of g mol-1. The term molecular weight is the ratio of the average mass per formula unit of a substance to - th of the mass of an atom of 12C and is dimensionless (IUPAC, 1991, in press). This text will use molecular weight throughout irrespective of the units, because molecular weight is the more familiar term for most chemists. 

When a particular food product is the sole source for nutrition, it is imperative that the amino acid profile be known. This information must be used to determine that the limiting (relative to metabolic need) amino acid is being supplied in sufficient quantity. A prime example of this category is infant formula. 

If we adopt the system of numbering each compd separately, and if the compd on the right side of the formula has simple arabic numerals (1,2,3, etc) counted clockwise, while the compd on the left side has primed arabic numerals 1, 2,3 etc, counted "counter-clockwise", then the formula may be represented as ... 

In rare cases in which a third ring compound is attached to one of the intermediate N atoms of an open chain nitrogen compound, its substituents would be numbered clockwise using double primes, as 1",2 ",3 , etc. In some cases the groups NH2, N02, etc may be attached to intermediate N atoms of the open N chain. Following is the formula of a complicated hypothetical compound ... 

Synonym marsh gas Formula CH4 MW 16.04 CAS [74-82-8] prime constituent of natural gas formed from petroleum cracking, decay of animal and plant remains, and anaerobic fermentation of municipality landfill contents occurs in marshy pools, landfill gas, and leachate from the landfill colorless and odorless gas lighter than air gas density 0.717 g/L liquefies at-161.4°C soluble in organic solvents, slightly soluble in water (25 mg/L) flammable gas. 

The entropy, enthalpy, and volume quantities appearing in Equations (10.1) and (10.2) are molar quantities, but care must be taken that such quantities refer to the same mass of material. This requirement is readily proved. Consider one phase, the primed phase, to contain ( ) moles of component based on a specified chemical formula, and assume that no chemical reaction takes place in this phase. Assume that the double-primed phase contains (h,)" moles of component but that a reaction, possibly polymerization or decomposition, takes place in this phase. The chemical reaction may be expressed as = i vfii = 0, where the sum is taken over all reacting species. The two Gibbs-Duhem equations may then be written as... 

As seen from the structural formulas in Figure 16.4, the organochlorine insecticides are of intermediate molecular mass and contain at least one aromatic or nonaromatic ring. They can be placed in four major chemical classes. The first of these consists of the chloroethylene derivatives, of which DDT and methoxychlor are the prime examples. The second major class is composed of chlorinated cyclodiene compounds, including aldrin, dieldrin, and heptachlor. The most highly chlorinated members of this class, such as chloredecone, are manufactured from hexachlorocyclo-pentadiene (see Section 16.3). The benzene hexachloride stereoisomers make up a third class of organochlorine insecticides, and the third group, known collectively as toxaphene, constitutes a fourth. 

Zinc chromate (ZnCr04), also known as zinc yellow (with the approximate formula 4Zn0K204Cr03-3H20), is used as a pigment because of its excellent corrosion-inhibiting effect both in mixed paints and as a priming coat for steel and aluminum. 

Normal lead styphnate has one lead atom per formula unit, whereas the basic form has two. A priming mixture using basic lead styphnate was patented in 1949 ... 

Complex Salt of Styphnic-Hypophosphoric Acids of the formula [CeH(N02)30K0] 2-Cu.Cu(H2 P02)2 was patented for use as a priming composition. Its prepn is described in Ref... 

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