Impurities common names

Marble. The word marble is used as the common name for two types of monomineral rocks one derived from limestone and therefore composed of calcium carbonate, the other derived from dolomite and composed of calcium magnesium carbonate. Extremely high pressures and heat during past geological times modified the structure of both limestone and dolomite, compacting them into a characteristic crystal structure. Most marble is white however, minor and trace amounts of metallic impurities cause the formation of stains in a variety of colors, hues, and patterns, or of colored marble. 

Composition/information on ingredients Substance Chemical identity. Common name, synonyms, etc. CAS number and other unique identifiers. Impurities and stabilizing additives which are themselves classified and which contribute to the classification of the substance. Mixture The chemical identity and concentration or concentration ranges of all ingredients which are hazardous within the meaning of the GHS and are present above their cut-off levels. NOTE For information on ingredients, the competent authority rules for CBI take priority over the rules for product identification. 

Animal fat (AAFCO number 33.1) is obtained from the tissues of mammals and/or poultry in the commercial processes of rendering or extracting. It consists predominantly of triacylglyerol esters of fatty acids and contains no additions of free fatty acids or other materials obtained from fats. It must contain, and be guaranteed for, not less than 90% total fatty acids, not more than 2.5% unsaponifi-able matter, and not more than 1% insoluble impurities. Maximum free fatty acids and moisture must also be guaranteed. If the product bears a name descriptive of its kind or origin (e.g., beef, pork, or poultry), it must correspond thereto. If an antioxidant is used, the common name or names must be indicated, followed by the words used as a preservative. Includes IFN 4-00-409 (animal poultry fat). 

Common name Not applicable Number of Identity CAS No. 44444-44-4 Impurities none... 

Calculation of the concentration of an analyte by expression 9.13 leads to an erroneous result if the sample contains an impurity (absent in the reference solution) which also absorbs at the wavelength of measurement. Therefore a method commonly named confirmatory analysis is used. 

The nomenclature for carboxylic acids follows the familiar pattern of adding the functional group name -oic acid to the named hydrocarbon chain except that the common names formic acid and acetic acid are still widely accepted. Thus, formic acid is methanoic acid, acetic acid is ethanoic acid, propionic acid is propanoic acid, and -butyric acid is butanoic acid. The CAS numbers (Chemical Abstract Service, American Chemical Society) for the carboxylic acids are listed in Table 6.1 along with the physical properties. The CAS numbers refer to the major carboxylic acid component. Refer to the Material Safety Data Sheet (MSDS) for CAS numbers of any minor impurities in the solvent. 

Zinc is an element of group 12 of the periodic table, of which the outer electrons are 3d 4s and zinc is in the same group of elements, such as Cd and Hg. Zinc exists as 70 ppm in the Earth s crust and exists in similar amounts to Cr (100 ppm) and Ni (80ppm) [1]. Zinc is produced from sphalerite (ZnS) as ores. There are two processes, a dry process and a wet process, for the refinement of zinc. However, zinc is largely produced by the wet process. The wet process is equally to be said as an electrolysis process. The sphalerite contains lead, iron cadmium and copper, etc. besides zinc and, by a flotation separation of the ores, the zinc concentrate (50-55 % Zn) and the lead concentrate are separated. The zinc concentrate is burnt and put into a vessel and dissolved in an electrolysis foul solution. The zinc sulfate solution and concentrated mud (the common name is red mud) are separated by a filter. Cadmium and copper, etc., as impurities dissolve in the zinc sulfate solution. Then zinc dust is added to the solution to precipitate these impurities to form a clean solution of zinc sulfate to be electrolyzed. In the electrolysis, lead containing 1 % of silver is used as a cathode and aluminum is used as an anode, and zinc is produced on the cathode [2—4]. The properties of zinc are shown in Table 5.1. 

Common name Eormula Mol. wt. (g/mol) Typicril impurities Comments... 

In addition to the above two commonly found impurities, there are a number of other acid radical impurities which exist in pharmaceutical substances, namely arsenate, carbonate, cyanide, nitrate, oxalate, phosphate and silicate. 

Cerium was the first rare-earth element discovered, and its discovery came in 1803 by Jons Jakob Berzelius in Vienna. Johann Gadohn (1760—1852) also studied some minerals that were different from others known at that time. Because they were different from the common earth elements but were all very similar to each other, he named them rare-earth elements. However, he was unable to separate or identify them. In the 1800s only two rare-earths were known. At that time, they were known as yttria and ceria. Carl Gustav Mosander (1797—1858) and several other scientists attempted to separate the impurities in these two elements. In 1839 Mosander treated cerium nitrate with dilute nitric acid, which yielded a new rare-earth oxide he called lanthanum. Mosander is credited with its discovery. This caused a change in the periodic table because the separation produced two new elements. Mosander s method for separating rare-earths from a common mineral or from each other led other chemists to use... 

The order and timing of the addition of reagents in the KA-process is varied but in a typical procedure three reagents, namely, acetic anhydride, a solution of ammonium nitrate in nitric acid, and solid hexamine dinitrate, are added slowly, in small portions and in parallel, into the reaction vessel which is preheated to 60-80 °C. On completion the reaction mixture is often cooled to 50-60 °C and the RDX filtered and sometimes washed with acetic acid. This process produces a product which melts over a 2 °C range but the RDX still contains up to 10 % HMX as a by-product. Dilution of the reaction mixture with water before removing the RDX produces a very impure product containing numerous unstable linear nitramine-nitrates. Based on the assumption that one mole of hexamine dinitrate produces two mole of RDX the KA-process commonly yields 75-80 % of RDX. 

One of the most common sources of contamination is the electrolyte since impurities in it would diffuse to the electrode and adhere to it during the course of the experiment. Impurities in the electrolyte can be reduced substantially by careful purification of solvent and solute. Distillation or ultrafiltration purifies water, the most common solvent. Usually solute materials can be bought in a very high purity, and whenever this is not the case, they can be cleaned by standard procedures such as recrystallization or calcination. Electrolysis of the electrolyte is also a common practice. Here, two sacrificial electrodes are immersed in the electrolyte and a potential is applied between them for about 36 hr in such a way that impurities are oxidized or reduced on their surfaces—the electrodes act as a garbage disposal thus the name of sacrificial electrodes. 

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