Bluish flame

The chemistry of such solutions has been alluded to on p. 678. At low temperatures a hydrate H28.5IH2O crystallizes. In acid solution H28 is also a mild reducing agent e.g. even on standing in air solutions slowly precipitate sulfur. The gas bums with a bluish flame in air to give H2O and 8O2 (or H2O and 8 if the air supply is restricted). For adducts, see p. 673. 

MPa. A reddish flame is seen above the bluish flame. On the other hand, no bluish and reddish flames are seen when the p(0.80) propellant burns at a pressure of 0.1 MPa, as shown in Fig. 7.4 (c). The flame is entirely yellowish, which can be ascribed to the fuel-rich nature of the diffusion flame generated by the gaseous decomposihon products of the binder and the AP parhcles.l Indeed, the flame... 

The heat flux transferred back from the gas phase to the burning surface is dependent on the temperature gradient in the gas phase, which is inversely proportional to the thickness of the reaction zone in the gas phase. Since the reaction in the gas phase is complete at the upper end of the bluish flame, the heat flux defined by Am conforms to the proportionality relationship Am l/6g p0- . The observed pressure dependence of the burning rate, is caused by the pressure depend-... 

When large spherical AP particles dg = 3 mm) are added, large flamelets are formed in the dark zone.Pl Close inspection of the AP particles at the burning surface reveals that a transparent bluish flame of low luminosity is formed above each AP particle. These are ammonia/perchloric acid flames, the products of which are oxidizer-rich, as are also observed for AP composite propellants at low pressures, as shown in Fig. 7.5. The bluish flame is generated a short distance from the AP particle and has a temperature of up to 1300 K. Surrounding the bluish flame, a yellowish luminous flame stream is formed. This yellowish flame is produced by in-terdiffusion of the gaseous decomposition products of the AP and the double-base matrix. Since the decomposition gas of the base matrix is fuel-rich and the temperature in the dark zone is about 1500 K, the interdiffusion of the products of the AP and the matrix shifts the relative amounts towards the stoichiometric ratio, resulting in increased reaction rate and flame temperature. The flame structure of an AP-CMDB propellant is illustrated in Fig. 8.1. 

When heated to 215° C., realgar decreases in weight owing to oxidation to arsenious oxide and sulphur dioxide 12 the reaction becomes more rapid with rise in temperature, and the sulphide finally inflames and bums with a bluish flame.13 The heat of the reaction representing the roasting process has been given as14... 

As already noted the hybrid bonds of benzene rings have the same stability as the carbon-carbon single bonds found in the alkanes. The aromatic compounds can enter into many reactions which do not affect the ring structure. The volatile aromatics are highly flammable and bum with a luminous, sooty flame in contrast to alkanes and alkenes, which bum with a bluish flame, leaving little carbon residue. 

Zinc is a bluish-white metal, malleable and ductile at 150°C, but at 180°C it changes rapidly so that at 205°C it may be easily powdered remains lustrous in dry air but is slightly tarnished in moist air or in water burns upon heating to vaporization with a bluish flame, forming zinc oxide soluble in acids—slowly when pure but rapidly on contact with copper or platinum soluble in alkalies. Discovery prehistoric. 

The pleasant odors of the derivatives of many arenes is the origin of the name aromatic hydrocarbons. The arenes themselves generally are quite toxic some are carcinogenic and inhalation of their vapors should be avoided. The volatile arenes are highly flammable and burn with a luminous sooty flame, in contrast to alkanes and alkenes, which usually burn with a bluish flame leaving little carbon residue. 

Acetic, CHg.COOH,—Colourless crystals M.P. 17° B.P. 119° characteristic odour vapour burns with bluish flame miscible in all proportions with water, alcohol and ether. 

Sulfur burns with a bluish flame to yield colorless SO2 gas. 

It consists of a cone uj pressed gray-white powder, which is ignited on afire-resistant surface. Bluish flames, out of which arose a fantastically shaped monster of a brownish-yellow color that was well suited to test one s memories of the Biblical story according to which Moses and his companions cast rods in front of the Pharaoh and transformed them into snakes. .. 

The use of OEC generally reduces the likelihood of emitting soot into the exhaust products because of the intensified combustion (see Figure 2.15) and higher flame temperatures, compared with air/fuel systems. Older style, high-intensity oxy/fuel burners usually had a very hot, bluish flame which was very nonluminous. The newer style oxy/fuel burners are much lower intensity and have a much higher luminosity. However, soot carryover into the exhaust has not been identified as a problem for OEC. 

Elemental bismuth is inert in dry air at room temperature, but oxidizes slowly to become covered with a thin film of the oxide, which gives it a beautiful multi-colored luster. Above its melting point, it oxidizes rapidly to form an oxide film. At red heat in air, it bums with a bluish flame to give a yellow fume of bismuth oxide (BiiOj). It can also be attacked by super-heated water vapor to form the yellow oxide. Heating with sulfur produces bismuth sulfide Bi2S3 as a dark brown to grayish black solid. 

Even now, in the stillness of death, the huge jaws seemed to be dripping with bluish flame, and the small, deep-set, cruel eyes were ringed with fire. I placed my hand upon the glowing muzzle, and as I held them up my own fingers smouldered and gleamed in the darkness. 

It is highly inflammable, and bums with a bluish flame, giving on CO, and SO, its vappr forms highly explosive mixtures with sir, which detonate on contact with a glass rod heated to 250 (482 F.). Irs vapor forms a mixture with nitrogen dioxide, which, when ignited, bxums with a brilliant flame, rich in actinic raya... 

Tri hydrate, crystals, granules. Slight odor. Liquefies in its water of hydration at about 60" Becomes anhydr at 120. Burns with a bluish flame, emitting a garlic-like odor. One gram dissolves in 0.5 ml water, 2.5 ml alcohol. pH about 8 9. Keep well closed. 

CHEMICAL PROPERTIES highly polar liquid bums with nonluminous, bluish flame reacts vigorously with oxidizing agents FP (12°C, 54°F) LFLAJFL (6.0%, 36.5%) AT (470°C, 878°F) HC (723 kJ/mol). 

This gas is combustible, burning with a bluish flame, and producing sulphurous acid gas and water. Its Sp. G. is 1 177. Water absorbs 2 or 3 times its volume of the gas, and acquires its smell and a nauseous sweetish taste. By contact with the air, the solution is gradually decomposed water is formed and sulphur deposited. Sulphuretted hydrogen water must, therefore, be kept in small phials, quite full and closely stopped. 

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