Metals strontium salts

Strontium is softer than calcium and decomposes in water more vigorously. It does not absorb nitrogen below 380oC. It should be kept under kerosene to prevent oxidation. Freshly cut strontium has a silvery appearance, but rapidly turns a yellowish color with the formation of the oxide. The finely divided metal ignites spontaneously in air. Volatile strontium salts impart a beautiful crimson color to flames, and these salts are used in pyrotechnics and in the production of flares. Natural strontium is a mixture of four stable isotopes. 

Barium and strontium salts of polystyrene with two active end-groups per chain were prepared by Francois et al.82). Direct electron transfer from tiny metal particles deposited on a filter through which a THF solution of the monomer was percolated yields the required polymers 82). The A.max of the resulting solution depends on the DPn of the formed oligomers, being identical with that of the salt of polymers with one active end-group per chain for DPn > 10, but is red-shifted at lower DPn. Moreover, for low DPn, (<5), the absorption peak splits due to chromophor-chromophor interaction caused by the vicinity of the reactive benzyl type anions. 

Strontium chloride is used to produce strontium metal by electrolysis. It also is used to prepare other strontium salts, as a desensitizer in dentistry, and in pyrotechnics. 

An aqueous solution of sulfuric acid and a salt of periodic add, trisodium paraperiodate, or one of the potassium periodates, has been used frequently as a substitute for pure periodic add. When the product of the oxidation reaction is to be isolated, the effect of the presence of metal ions on the yield should be considered. If the product is volatile or slightly soluble, or is isolated either as a slightly soluble derivative or by extraction with organic solvents, the presence of metal ions should not reduce the yield. In the Case of certain methylhexosides34 which were oxidized by periodic acid formed from potassium metaperiodate and an equivalent of sulfuric add in aqueous solution, the presence of potassium ions was found to cause a low yield of the crystalline strontium salt prepared by the strontium hypobromite oxidation of the dialdehyde resulting from the periodic add reaction. Oxidation by pure periodic add, a solution of which is prepared either from crystalline paraperiodic add or by the previously mentioned method from potassium metaperiodate, is desirable when the presence of difficultly removed metal ions affects the yield adversely. 

Trivalent chromium compounds, except for acetate, nitrate, and chromium(III) chloride-hexahydrate salts, are generally insoluble in water. Some hexavalent compounds, such as chromium trioxide (or chromic acid) and the ammonium and alkali metal (e.g., sodium, potassium) salts of chromic acid are readily soluble in water. The alkaline metal (e.g., calcium, strontium) salts of chromic acid are less soluble in water. The zinc and lead salts of chromic acid are practically insoluble in cold water. Chromium(VI) compounds are reduced to chromium(III) in the presence of oxidizable organic matter. However, in natural waters where there is a low concentration of reducing materials, chromium(VI) compounds are more stable (EPA 1984a). For more information on the physical and chemical properties of chromium, see Chapter 3. 

For salts of nitric acid while sodium salts, potassium salts,cesium salts, and ammonium salts show comparatively vigorous deflagration, lithium salts, strontium salts and silver salts show milder deflagration. Other metal salts of acids show almost no increase in pressure due to ignition. 

It is possible to insert additional atoms or molecules into the inter-lamellar gap of many layer-lattice materials, including molybdenum disulphide, creating what are called intercalation compounds. The intercalated substances may be alkali or alkalyne-earth metals (sodium, potassium, rubidium, caesium, calcium, strontium), salts or organic bases such as ethylene diamine or pyridine . 

Metallic strontium dissolves inliquid ammonia. The metal and its salts impart a briUiant red color to flames. 

Typical fuels are magnesium (sometimes mixed with aluminum), manganese, and silicon. Typical oxidizers include the nitrates of barium, sodium, potassium, and strontium. Binders used are castor and linseed oils and paraffin waxes. Another interesting flare mix is magnesium or teflon. The chlorine and fluorine from the teflon are the oxidizers in this mix. Magnesium or teflon flares burn several hundred degrees (°C) hotter than metal or salt flares and radiate very strongly in the infrared spectrum. 

The flame of an alcohol lamp looks almost colourless. Vhen a length of platinum v/ire which is dipped into a metal salt solutioh is put into the flame, the flame is coloured in the upper part by the wire. The colour is peculiar to the kind of the metal strontium colours the flame red, sodium yellow, barium pale green and copper blue. This is applied to the qualitative analysis of metal ions as the colour flame test. The emission of the coloured light is caused by atomic metal gas or a gas consisting of molecules of metal compound, and the process may be set out as follows ... 

Review the "Stoichiometry chapter for information about mass-mass stoichiometry. In this investigation, you will use a double-displacement reaction, but Na2C03 will be used as a reagent to identify how much calcium is present in a sample. Like strontium and other Group 2 metals, calcium salts react with carbonate-containing salts to produce an insoluble precipitate. 

Strontium is a naturally occurring element found in rocks, soil, dust, coal, and oil. Naturally occurring strontium is not radioactive and is referred to as stable strontium. Stable strontium in the environment exists in four stable isotopes, " Sr (read as strontium 84), Sr, Sr, and Sr. Twelve other unstable isotopes are known to exist. Its radioactive isotopes are Sr and °Sr. Strontium is chemically similar to calcium. It was discovered in 1790. The isotope Sr is a highly radioactive poison, and was present in fallout from atmospheric nuclear explosions and is created in nuclear reactors. Atmospheric tests of nuclear weapons in the 1950s resulted in deposits and contaminations. °Sr has a half-life of 28 years and is a high-energy beta emitter. Its common cationic salts are water soluble it forms chelates with compounds such as ethylenediaminetetraacetic acid strontium coordination compounds are not common. Powdered metallic strontium may constitute an explosion hazard when exposed to flame. 

GUNPOWDER, or black powder, is a mixture of saltpetre, sulphur and carbon. Early Chinese recipes used equal weights to make a fast burning, but not explosive, powder. A composition that matches well the chemistry ctf the reaction is 15 parts saltpetre, 2 parts sulphur and 3 parts charcoal. Mix the ingedients while damp, using pressure to make a dense cake which can be broken into grains when dry. For most explosive results use refined saltpetre. Metal salts can add colour to the explosion, e.g. sodium salts for yellow or orange, potassium salts for purple, and strontium salts for red. This is the basis of fireworks. 

Strontium salts are used in fireworks and flares, which show the characteristic red glow of strontium in a flame. Strontium chloride is used in some toothpastes for persons with sensitive teeth. The metal itself has no practical uses. 

Salts of rare earth metals Strontium carbonate,... 

Other solvates are well known. The first examples of monomeric six-coordinate (octahedral) complexes of strontium salts have recently been characterized, viz. /ranj-[Srl2(hmpa)4l and cis-[Sr(NCS)2(hmpa)4] where hmpa is (MeiN) they were made as colourless crystals by refluxing a mixture of NH4I (or NH4SCN) with metallic Sr and hmpa in toluene for 1 hour. ... 

Commercial products are often unsatisfactory in kinetic studies. Preparation of some commonly used initiators is given elsewhere141. Benzyl sodium is prepared from mercury dibenzyl and metallic sodium123 a similar technique yields barium and strontium salts. Fluorenyl lithium, sodium etc., are conveniently prepared from fluorene and a suitable organo-metallic compound, e.g. 

CHROMIC ACID, STRONTIUM SALT (7789-06-2) SrCrO A strong oxidizer accelerates the burning of combustible materials. Violent reaction with reducing agents active metals, cyanides, esters, and thiocyanates. Incongjatible with acids, bases, water, fluorine, hydrazine, zirconium dusts, potassiiun iodide, sodium tetraborate, sodium tetraborate decahydrate, sodium borohydride. 

NITRIC ACID, STRONTIUM SALT (10042-76-9) A powerful oxidizer. React violently with reducing agents, acetic anhydride, ferf-butylhydroperoxide, metal cyanides, thiocyanates, sodium acetylide. Incompatible with amines, ammonium hexacyanoferrate(II), boranes, cyanides, citric acid, esters, hydrazinium perchlorate, isopropyl chlorocarbonate, nitrosyl perchlorate, organic azides, organic bases, sodium thiosulfate, sulfamic acid. 

Silvery-white metal face-centered cubic structure rapidly becomes yellow on exposure to air and assumes an oxide film. The finely divided metal ignites spontaneously in air. d 2.6 mp 757 I bp 1366. E (aq) SF+ /Sr -2.89 V. For a description of reactions which are characteristic of at -kaline earth metals see Calcium. Keep under liquid containing no oxygen. The heated metal combines with hydrogen to form strontium hydride and with nitrogen to form strontium nitride. Strontium salts impart brilliant red color to a flame. 

The precipitation capacity of sodium rhodizonate is particularly interesting within the group of the alkaline earth metals. Barium gives a red-brown precipitate of barium rhodizonate. Strontium salts react in the same way with rhodizonates, but calcium salts do not. Under suitable conditions, however, barium may be identified in the presence of strontium. The rhodizonate test is thus recommended for the detection of barium within the ammonium carbonate (alkaline earth) group, or for its detection when bivalent heavy metals are known to be absent. 

The above mentioned Schiff base (I) forms with metal ions colored inner complex salts. Solutions of calcium, barium and strontium salts when... 

Alkali bromides, chlorides, sulfates, and nitrates interfere only when very small amounts of iodide are to be detected. Bromides have the greatest deleterious effect however, when the amount of bromide is approximately known, small amounts of iodine may still be detected if a comparative test is carried out. Metal salts which give colored aqueous solutions interfere (Fe , UOa, Ni, Cu, Co). Cyanides, mercuric, silver, and manganese salts impair the reaction, as do compounds which reduce Ce. In such cases the difficulty may occasionally be averted by using more concentrated ceric solutions. Under the experimental conditions, barium and strontium salts are precipitated as sulfates, which are colored yellow by coprecipitation of ceric salt. Osmium salts behave similarly to iodides. 

Among the alkaline earth metals, only barium and strontium salts react in neutral solution with sodium rhodizonate (see page 119) they form brown-red precipitates. To detect strontium in the presence of barium, the latter must therefore be converted into a compound which does not react with sodium rhodizonate. Insoluble barium chromate is suitable, since strontium chromate is sufficiently soluble in water to react normally with sodium rhodizonate. 

Alkali metal and alkaline earth metal salts of AzTZ are mostly soluble in water with the exception of the barium and strontium salts that are almost insoluble [89]. The potassium salt is hardly soluble in cold water, but more soluble in hot water [2]. The mercury and lead salts are also almost insoluble [90]. The lead salt is insoluble in inorganic solvents but soluble in weak acids and bases. The monobasic salt is insoluble in water and slightly soluble in most organic solvents. The best solvent for this salt is diluted nitric acid or a solution of ammonium acetate [2]. 

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