Ammonia physical properties

Some of the physical properties of fatty acid nitriles are Hsted in Table 14 (see also Carboxylic acids). Eatty acid nitriles are produced as intermediates for a large variety of amines and amides. Estimated U.S. production capacity (1980) was >140, 000 t/yr. Eatty acid nitriles are produced from the corresponding acids by a catalytic reaction with ammonia in the Hquid phase. They have Httie use other than as intermediates but could have some utility as surfactants (qv), mst inhibitors, and plastici2ers (qv). 

Physical Properties. The physical form and stabiUty of a fertilizer product is of an importance almost equal to that of its chemical content. Commercial fertilizers of importance include not only soHds, but also fluids, both solutions and suspensions, and even a gas (anhydrous ammonia). 

Ethyleneimine (El) and its two most important derivatives, 2-methyla2iridine [75-55-8] (propyleneimine) (PI) and l-(2-hydroxyethyl)a2iridine [1072-52-2] (HEA) are colodess Hquids. They are miscible ia all proportions with water and the majority of organic solvents. Ethyleneimine is not miscible with concentrated aqueous NaOH solutions (>17% by weight) (24). Ethyleneimine has an odor similar to ammonia and is detectable only at concentrations >2 ppm. The physical properties of ethyleneimine and the derivatives mentioned are given ia Table 1. Thermodynamic data can be found ia the Hterature (32). 

Lead Fluoride. Lead difluoiide, Pbp2, is a white oithorhombic salt to about 220°C where it is transformed into the cubic form some physical properties ate given in Table 1. Lead fluoride is soluble in nitric acid and insoluble in acetone and ammonia. It is formed by the action of hydrofluoric acid on lead hydroxide or carbonate, or by the reaction between potassium fluoride and lead nitrate. 

Lead Chloride. Lead dichloride, PbCl2, forms white, orthorhombic needles some physical properties are given in Table 1. Lead chloride is slightly soluble in dilute hydrochloric acid and ammonia and insoluble in alcohol. It is prepared by the reaction of lead monoxide or basic lead carbonate with hydrochloric acid, or by treating a solution of lead acetate with hydrochloric acid and allowing the precipitate to settle. It easily forms basic chlorides, such as PbCl Pb(OH)2 [15887-88 ] which is known as Pattinson s lead white, an artist s pigment. 

STMP reacts with other nucleophiles such as aqueous ammonia to yield amidophosphates, which contains a P—N bond. STMP is used for the modification of the physical properties of starch and proteins by reaction with the amino and hydroxyl groups. 

Table 1. Physical Properties of Alkanolamines Prepared from Ammonia and Olefin Oxides...

Pyrrole is a colorless, slightly hygroscopic Hquid which, if fresh, emits an odor like that of chloroform. However, it darkens on exposure to air and eventually produces a dark brown resin. It can be preserved by excluding air from the storage container, preferably by displacement with ammonia to prevent acid-catalyzed polymerization. A review of the physical and theoretical aspects of pyrrole is found in Reference 4. Some physical properties of pyrrole are Hsted in Table 1. 

Physical Properties. Ammonium thiocyanate [1762-95-4] NH SCN, is a hygroscopic crystalline soHd which deHquesces at high humidities (375,376). It melts at 149°C with partial isomerization to thiourea. It is soluble in water to the extent of 65 wt % at 25°C and 77 wt % at 60°C. It is also soluble to 35 wt % in methanol and 20 wt % in ethanol at 25°C. It is highly soluble in Hquid ammonia and Hquid sulfur dioxide, and moderately soluble in acetonitrile. 

The level of technical service support provided for a given product generally tracks in large part where the suppHer considers thek product to be located within the spectmm of commodity to specialty chemicals. Technical service support levels for pure chemicals usually provided in large quantities for specific synthetic or processing needs, eg, ammonia (qv), sulfuric acid (see SuLFURic ACID AND SULFURTRIOXIDe), formaldehyde (qv), oxygen (qv), and so forth, are considerably less than for more complex materials or blends of materials provided for multistep downstream processes. Examples of the latter are many polymers, colorants, flocculants, impact modifiers, associative thickeners, etc. For the former materials, providing specifications of purity and physical properties often comprises the full extent of technical service requked or expected by customers. These materials are termed undifferentiated chemicals (9),... 

Promoters. Many industrial catalysts contain promoters, commonly chemical promoters. A chemical promoter is used in a small amount and influences the surface chemistry. Alkali metals are often used as chemical promoters, for example, in ammonia synthesis catalysts, ethylene oxide catalysts, and Fischer-Tropsch catalysts (55). They may be used in as Httie as parts per million quantities. The mechanisms of their action are usually not well understood. In contrast, seldom-used textural promoters, also called stmctural promoters, are used in massive amounts and affect the physical properties of the catalyst. These are used in ammonia synthesis catalysts. 

At room temperature and atmospheric pressure ammonia is a colourless, alkaline gas with a pungent smell. It dissolves readily in water. Physical properties are summarized in Table 9.6. The effect of temperature on vapour pressure of anhydrous ammonia is shown in Figure 9.2. 

W. L. Jolly and C. J. Hallada, Liquid ammonia. Chap. 1 in T. C. WaDDINGTON (ed.), Non-aqueous Solvent Systems, pp. 1-45, Academic Press, London, 1965. J. C. Thompson, The physical properties of metal solutions in non-aqueous solvents. Chap. 6 in J. Lagowski (ed.). The Chemistry of Non-aqueous Solvents, Vol. 2, pp. 265-317, Academic Press, New York, 1967. J. Jander (ed.). Chemistry in Anhydrous Liquid Ammonia, Wiley, Interscience, New York, 1966, 561 pp. 

Ammonia is a pungent, toxic gas that condenses to a colorless liquid at — 33°C. The liquid resembles water in its physical properties, including its ability to act as a solvent for a wide range of substances. Because the dipole moment of the NH3 molecule (1.47 D) is lower than that of the H20 molecule (1.85 D), salts with strong ionic character, such as KCI, cannot dissolve in ammonia. Salts with polarizable anions tend to be more soluble in ammonia than are salts with greater ionic character. For example, iodides are more soluble than chlorides in ammonia. Liquid ammonia undergoes much less autoprotolysis than water ... 

---