Flame metals

Picric acid is used on a large scale as a high explosive, but for this purpose requires a detonator. If a few small crystals of the pure acid are heated on a crucible lid, they first melt, and ultimately burn harmlessly with a smoky flame. Metallic salts of picric acid are much less stable than the free acid,... 

It also reacts violently with lithium in the molten state as well as with sodium, causing emissions of flaming metal. The reaction takes place with pure sodium as well as with sodium combined with calcium or sodium oxide. 

As additives to reduce soot output in flames, metal and organometallic compounds, such as ferrocene, have attracted the attention of many investigators (see Ref. [113]). The effect in premixed flames is best described by Bonczyk [114], who reported that the efficiency with which a given metal affects soot production characteristics depends almost exclusively on temperature and the... 

This is the flame metal content expressed as a partial pressure. 

Spectral interference because of scattering by products of atomization is most often encountered when concentrated solutions containing elements such asTi, /.r. and W —which form refractory oxides-arc aspirated into the flame. Metal oxide particles with diameters greater than the wavelength of light appear to be formed, and scattering of the incident beam results. 

Thus hydrogen rich fuels should be avoided in purple flames. Metal fuels and charcoal would be desirable fuels, and Dechlorane should be desirable as a chlorine donor. Douda suggested that high flame temperatures might be useful because monohydroxides are probably less temperature stable than monochlorides. 

T. Fish, Green and Other Colored Flame Metal Fuel Compositions Using Parlon , PyrotechnicaVll, 1981. 

Dapalm The aluminium soap of naphthenic and palmitic acids used to gel gasoline. The thickened gasoline has been used for military flame throwers and incendiary bombs. See metallic soaps. 

Note that some of the metals frequently encountered in simple organic compounds give characteristic flame colorations Na, yellow K, lilac through blue glass Ca, brick-red Ba, apple-green Cu, bright blue-green. Ag and Pb, no characteristic flame. 

Suspend the bomb by a wire or a metal rod through F. Fill with water the annular space between the pillar F and the hole in the top of H. Now heat the base of A with a pointed flame, e.., from a blowpipe pointing upwards. The time required for heating in this way is usually about i minute, but an ordinary Bunsen flame, used without concentration on the bottom of A, may require about 4 minutes. The... 

A shallow metal vessel containing sand, the so-called sand bath, heated by means of a flame, was formerly employed for heating flasks and other glass apparatus. Owing to the low heat conductivity of sand, the temperature control is poor the use of sand baths is therefore not... 

If an appreciable amount of residue remains, note its colour. Add a few drops of water and test the solution (or suspension) with htmus or with Universal indicator paper. Then add a httle dilute hydrochloric acid and observe whether efiervesceiice occurs and the residue dissolves. Apply a flame test with a platinum wire on the hydrochloric acid solution to determine the metal present. (In rare cases, it may be necessary to subject a solution of the residue to the methods of qualitative inorganic analysis to identify the metal or metals present.) If the flame test indicates sodium, repeat the ignition of the substance on platinum foil. 

Evidence of the organic nature of the substance may, be provided by the behaviour of the compound when heated on porcelain or platinum or other comparatively inert metal (e.g., nickel) the substance is inflammable, burns with a more or less smoky flame, chars and leaves a black residue consisting largely of carbon (compare Ignition Test above). 

Step 3. The non-steam-volatile compounds. The alkaline solution (82) remaining in the distiUing flask from Step 2 may contain water-soluble, non-volatile acidic, basic or neutral compounds. Add dilute sulphuric acid until the solution is just acid to Congo red, evaporate to dryness, and extract the residual solid with boiling absolute ethyl alcohol extraction is complete when the undissolved salt exhibits no sign of charring when heated on a metal spatula in the Bunsen flame. Evaporate the alcoholic solution to dryness and identify the residue. 

Lithium is presently being recovered from brines of Searles Lake, in California, and from those in Nevada. Large deposits of quadramene are found in North Carolina. The metal is produced electrolytically from the fused chloride. Lithium is silvery in appearance, much like Na and K, other members of the alkali metal series. It reacts with water, but not as vigorously as sodium. Lithium imparts a beautiful crimson color to a flame, but when the metal burns strongly, the flame is a dazzling white. 

Fluorine is the most electronegative and reactive of all elements. It is a pale yellow, corrosive gas, which reacts with most organic and inorganic substances. Finely divided metals, glass, ceramics, carbon, and even water burn in fluorine with a bright flame. 

As with other metals of the alkali group, it decomposes in water with the evolution of hydrogen. It catches fire spontaneously on water. Potassium and its salts impart a violet color to flames. 

Rubidium can be liquid at room temperature. It is a soft, silvery-white metallic element of the alkali group and is the second most electropositive and alkaline element. It ignites spontaneously in air and reacts violently in water, setting fire to the liberated hydrogen. As with other alkali metals, it forms amalgams with mercury and it alloys with gold, cesium, sodium, and potassium. It colors a flame yellowish violet. Rubidium metal can be prepared by reducing rubidium chloride with calcium, and by a number of other methods. It must be kept under a dry mineral oil or in a vacuum or inert atmosphere. 

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. 

Benzoyl peroxide Direct sunlight, sparks and open flames, shock and friction, acids, alcohols, amines, ethers, reducing agents, polymerization catalysts, metallic naph-thenates... 

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