Smoky

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,... 

Aniline.—Burns with a very smoky flame, clouds of soot being produced. Typical of many aromatic substances. i,2 Dibromoethane.—Does not burn until vapour becomes hot and then burns with a slightly smoky flame. Typical of substances rich in halogens such as cldoroform, chloral hydrate, and carbon, tetrachloride. (Note, however, that iodoform evolves copious fumes of iodine when heated in this way.)... 

Method 2. Mix 1 0 g. of 3 5-dinitrobenzoic acid with 1 5 g. of phosphorus pentachloride in a small, dry test-tube. Warm the mixture gently over a small smoky fiame to start the reaction when the reaction has subsided (but not before), boil for 1-2 minutes or until the solid matter has dissolved. Pour the mixture while still liquid on a dry watch glass (CAUTION the fumes are irritating to the eyes). When the product has solidified, remove the liquid by-product (phosphorus oxychloride) by transferring the pasty mixture to a pad of several thicknesses of filter paper or to a small piece of porous tile. Spread the material until the liquid has been absorbed and the residual solid is dry. Transfer the 3 5 dinitrobenzoyl chloride to a test-tube, add 0-5-1 ml. of the alcohol, and continue as in Method 1. 

Push one end of a length of 20 cm. of stout copper wire into a cork (this wUl serve as a holder) at the other end make two or three turns about a thin glass rod. Heat the coil in the outer mantle of a Bunsen dame until it ceases to impart any colour to the dame. Allow the wire to cool somewhat and, while still warm, dip the coil into a small portion of the substance to be tested and heat again in the non-luminous dame. If the compound contains a halogen element, a green or bluish-green dame will be observed (usually after the initial smoky dame has disappeared). Before using the wire for another compound, heat it until the material from the previous test has been destroyed and the dame is not coloured. 

Aromatic aldehydes usually have relatively high boiling points, but distil with little or no decomposition. The vapours burn with a smoky flame. They are easily oxidised on standing in the air into the corresponding acids the odours are often pleasant and characteristic. Aromatic aldehydes, by virtue of their high molecular weight, yield... 

Aromatic carboxylic acids are usually crystalline sohds, bum with a smoky flame, and are generally sparingly soluble in water. They may be detected and characterised as already described under Aliphatic Carboxylic Acids (Section 111,85). 

Aromatic esters usually burn with a smoky flame, possess reasonably high boiling points, and are (particularly esters of phenols) sometimes crystalline solids. Phenyl esters usually give phenol upon distillation with soda hme (see Section IV,175 for general details). 

Aromatic alcohols are insoluble in water and usually burn with a smoky flame. Their boiling points are comparatively high some are solids at the ordinary temperature. Many may be oxidised by cautious addi-tion of dilute nitric acid to the corresponding aldehyde upon neutralis-tion of the excess of acid, the aldehyde may be isolated by ether extraction or steam distillation, and then identified as detailed under Aromatic Aldehydes, Section IV,135. 

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). 

Quartz. When colorless, quart2 [14808-60-7] is also known as rock crystal. When irradiated, it becomes smoky from a color center associated with a ubiquitous Al impurity at about the 0.01% level. The name citrine [14832-92-9] is used when quart2 is colored by Fe, and irradiation of this can produce the purple-colored amethyst [14832-91-8] under certain circumstances (2). Although not signiftcandy lower priced than the natural materials, synthetic citrine and amethyst ate used in jewelry because of the abiUty to provide matched sets of stones from large, up to 7-kg, hydrothermaHy grown crystals. 

The electron can be trapped, for example by an interstitial which is converted to an H atom. The AlO is the hole color center which absorbs light and gives the color to smoky quart2. Bleaching is the result of thermal energy releasing the trapped electron, which then produces the reverse of reaction 1. The amethyst color center in quart2 is exactly like the smoky, except that Fe " replaces. ... 

An example of a hole color center is smoky quart2 [14808-60-7]. Here itradiation (either produced by nature or in the laboratory) of Si02 containing a trace of A1 ejects an electron from an oxygen adjacent to the A1 or, in customary nomenclature [AlO ] — [AlO ]" + e the ejected electrons are... 

Satisfactory engine performance is assured by maintaining a minimum log that allows comparison of present characteristics with past records of (1) cylinder exhaust, cooling water, and supercharger exhaust temperature for similar loadings, (2) running sounds and smokiness of exhaust, and (3) engine efficiency and losses. 

One of the reasons the tribes of early history were nomadic was to move periodically away from the stench of the animal, vegetable, and human wastes they generated. When the tribesmen learned to use fire, they used it for millennia in a way that filled the air inside their living quarters with the products of incomplete combustion. Examples of this can still be seen today in some of fhe more primitive parts of the world. After its invention, the chimney removed the combustion products and cooking smells from the living quarters, but for centuries the open fire in the fireplace caused its emission to be smoky. In ad 61 the Roman philosopher Seneca reported thus on conditions in Rome ... 

As soon as I had gotten out of the heavy air of Rome and from the stink of the smoky chimneys thereof, which, being stirred, poured forth whatever pestilential vapors and soot they had enclosed in them, I felt an alteration of my disposition. 

In developing countries, priorities have often been different. Industrialization, water and food supply and sanitation, infrastructure improvements, and basic health care are often the focus of the leaders of a country. In some areas, the availability of a job is much more problematic than some consideration about the quality of the air in the workplace or the home. Many dwellings in developing countries do not have closable windows and doors, so the outdoor and indoor air quality issues are different. In some houses where cooking is done by firewood or charcoal, the air quality outdoors may be considerably better than that inside the smoky residence. 

In a i-l. round-bottomed flask fitted with a reflux condenser protected by a calcium chloride tube 46 g. (2 gram atoms) of sodium is dissolved in 600 cc. of absolute alcohol (Note i). About one hour is required for the addition of the sodium, and another hour for its complete solution. Toward the end of the reaction the flask may be heated with a small smoky flame. While the sodium is being dissolved, the following materials are weighed in dry, stoppered containers 58 g. (r mole) of dry acetone (Note 2), 150 g. (1.03 moles) of freshly distilled ethyl oxalate (Org. Syn. Coll. Vol. i, 256), and 160 g. (i.i moles) of ethyl oxalate. 

Smoky Mountains National Park, spruce-fir forest is a sensitive receptor indicator. 

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