Precipitation analytical reagents

Table 11.20 Elements Precipitated by General Analytical Reagents...

Dilead hexacyanokisferrate [14402-61 -0] Pb2[Fe(CN)g], is a white precipitate that forms when lead acetate is added to Ca2[Fe(CN)g]. It is insoluble in water or dilute acids but is soluble in hot ammonium chloride or ammonium succinate solutions. It has been used as a quaUtative analytical reagent in tests for cadmium and chromate. 

Heteropolyacids (HPA) are the unique class of inorganic complexes. They are widely used in different areas of science in biochemistry for the precipitation of albumens and alkaloids, in medicine as anticarcinogenic agents, in industry as catalysts. HPA are well known analytical reagents for determination of phosphoms, silica and arsenic, nitrogen-containing organic compounds, oxidants and reductants in solution etc. 

TABLE 11.20 Elements Precipitated by General Analytical Reagents This table includes the more common reagents used in gravimetric determinations. The lists of elements precipitated are not in all cases exhaustive. The usual solvent for a precipitating agent is indicated in parentheses after its name or formula. When the symbol of an element or radical is italicized, die element may be quantitatively determined by the use of the reagent in question. ... 

Reagent Analyte and form precipitated Analyte form weighed... 

This materia] is 96.5% pure as determined by precipitation of the nickel compound and is satisfactory as an analytical reagent. 

Thioacetamide has been used for a long time as an analytical reagent to precipitate metal sulphides (see Ref. 2 for many relevant references). Thioacetamide can be hydrolyzed over a wide range of pH and is often used for CD in acidic baths. In a strongly acidic bath (pH < ca. 2), H2S is formed ... 

Some qualitative analytical reagents for the detection of rare earths elements are given in Tables 1.26 and 1.27. Gravimetric, volumetric, complexometric, precipitation and polarographic methods of analysis of rare earths are summarized in Tables 1.28 to 1.32. 

REAGENT ANALYTE AND FORM PRECIPITATED ANALYTE FORM WEIGHED... 

During the fifteenth century the metals zinc, antimony, bismuth, and probably cobalt were discovered, together with many new reactions now used in quantitative analysis. For example, A. Libavius (1540-1616) noted how ammonia in water could be determined by the blue color formed with a copper salt. Robert Boyle (1627-1691) was the first to use a solution of hydrogen sulfide (which he made from flowers of sulfur, potash, and ammonium chloride) as an analytical reagent, and he noted the black precipitate it formed with lead, gold, and mercury. 

Initially, sodium tetraphenylborate was used as a quantitative analytical reagent to precipitate group I elements [100]. This initial use was modified to precipitate group I elements [100]. This initial use was modified to precipitate and remove Cs-radioactive waste [101]. 

Use Analytical reagent, especially for separation and precipitation of metals, e.g., copper, iron, vanadium. 

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