Ammonia vapour

To counteraa chlorine or bromine fumes if inhaled in only small amounts, inhale ammonia vapour. Afterwards suck eucalyptus pastilles, or drink warm dilute peppermint or cinnamon essence, to soothe the throat and lungs. 

Primary aromatic amides are crystaUine sohds with definite melting points. Upon boiling with 10-20 per cent, sodium or potassium hydroxide solution, they are hydrolysed with the evolution of ammonia (vapour turns red htmus paper blue and mercurous nitrate paper black) and the formation of the alkah metal salt of the acid ... 

Ammonia phenols Ammonia vapour in a closed chamber various coloured spots... 

Phosgene [75-44-5] M 98.9, b 8.2 /756mm. Dried with Linde 4A molecular sieves, degassed and distilled under vacuum. This should be done in a closed system such as a vacuum line. HIGHLY TOXIC, should not be inhaled. If it is inhaled operator should lie still and made to breath ammonia vapour which reacts with phosgene to give urea. 

Figure 9.2 Ammonia vapour pressure versus temperature...

Single-phase a-brasses are susceptible to stress-corrosion cracking in the presence of moist ammonia vapour or certain ammonium compounds Here the predominant metallurgical variable is alloy composition, and in... 

The use of aqueous foams to control fume or vapour release from reactive chemicals is discussed. An acid-resistant foam NF2 controlled fume emission from 35% and 65% oleum, and from titanium tetrachloride, but was not effective for sulfur trioxide and chlorosulfuric acid. An alcohol-resistant foam NF1 suppressed ammonia vapour emission by 80%, and Universal fire foam reduced evaporation of ethylene oxide, vinyl chloride and methanethiol, and reduced vapour emission of 1,3-butadiene by 60%. Safety aspects of foam blanketing are discussed [1]. Equipment and application techniques are covered in some detail [2],... 

Pellizzari reported in 1884 a study of the reaction of dry ammonia vapours with dried and pulverized phenols and carboxyhc acids [17]. However, in spite of this early beginning, a systematic exploration of solvent-less processes of this type was not undertaken until the early 1970s by Paul and Curtin [18-20] and subsequently by others [21]. 

Although the reaction of alkali acetylides with oxirane proceeds slowly in liquid ammonia 15], it is an excellent method for preparing "homo-propargylic alcohols in quantities of 1 mol or more [2). Since oxirane is very volatile, considerable losses could occur if it is allowed to be swept along with the escaping ammonia vapour. One solution is to carry out the reaction under reflux, using a special condenser filled with dry ice and acetone. This would require regular addition of dry ice over a period of at least 12 h. It is much simpler to mix the acetylide... 

A filtered solution of 0.50 mol of potassium amide in -300 ml of liquid ammonia is prepared as described in refs. 1,3, and 4. The solution is concentrated to a volume oflOO to 150 ml by placing the flask in a water bath at 35 C (only the lower part of the flask is dipping in the water]. 1,3-Diaminopropane (350 ml, dried over machine-powdered KOH and subsequently distilled in a vacuum) is cautiously added to the remaining very concentrated solution of potassium amide. An efficient reflux condenser equipped with a narrow outlet (on the top) is placed on the flask, which is subsequently placed in a water bath at - 50"C. The flask is occasionally swirled by hand. When the stream of ammonia vapour has become very faint, the outlet is connected with a 20 cm long tube filled with KOH pellets, which in its turn is... 

Caffeine and other purine derivatives can be detected by the Murexide test. In this test the alkaloids are mixed with a tiny amount of potassium chlorate and a drop of hydrochloric acid and evaporated to dryness, and the resulting residue is exposed to ammonia vapour. Purine alkaloids produce pink colour in this test. 

An intimate mixture ot 274 grms. of rubidium iron alum, or 260 grms. of rubidium aluminium alum with 100 grms. of calcium carbonate, and 27 grms. of ammonium chloride, is heated in a nickel crucible to a dull red heat until ammonia vapours are no longer evolved, and then the temp, is raised to redness. The product is ground with a litre of cold water for 15 minutes filtered by suction and washed with 400 c.c. of water, added in small portions at a time. The combined sulphuric acid is precipitated by the addition of barium hydroxide, and the filtered liquid boiled while a stream of carbon dioxide is passed through the soln. If the soln. loses its alkaline reaction, and yet retains some calcium, a little rubidium carbonate must be added to precipitate calcium carbonate. The soln. is then treated with hydrochloric acid and evaporated. 

Zinc dust, hexachloroethane and aluminium Phosphorous pentoxide and phosphoric acid Sulfur, potassium nitrate and pitch Potassium chlorate, naphthalene and charcoal Zinc dust, hexachloroethane and naphthalene Silicon tetrachloride and ammonia vapour Auramine, potassium chlorate, baking soda and sulfur Auramine, lactose, potassium chlorate and chrysoidine Rhodamine red, potassium chlorate, antimony sulfide Rhodamine red, potassium chlorate, baking soda, sulfur Auramine, indigo, potassium chlorate and lactose Malachite green, potassium chlorate, antimony sulfide Indigo, potassium chlorate and lactose Methylene blue, potassium chlorate, antimony sulfide... 

Both methods have advantages and limitations. The latter approach allows dry development, for example with ammonia vapour, but there also exists the possibility of premature, indiscriminate coupling. The one-component system does not suffer from this instability, but its processing is a wet operation, which itself leads to instability of the final image. 

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