Ammonia - Water

Method Edwards, Maurer, Newman Prausnitz, AIChE J (1978) Experimental Data Source  

Macriss, et al, IGT34 (1964) Clifford Hunter, JPC 37 (1933) Temperature 60.0 degrees Celsius Experimental data  

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Using the relationship from the preceding section that the effective electronega tivity of carbon m a C—H bond increases with its s character (sp < sp < sp) the order of hydrocarbon acidity behaves much like the preceding methane ammonia water hydrogen fluonde series... 

Sodium bicarbonate may be prepared by the ammonia-salt (Solvay) process. Carbon dioxide is passed through a solution of sodium chloride in ammonia water. Sodium bicarbonate is precipitated and the ammonium chloride remains in solution. The ammonium chloride is heated with lime to regenerate ammonia (see Alkali AND CHLORINE PRODUCTS). 

Absorption Systems. Absorption refrigeration cycles employ a secondary fluid, the absorbent, to absorb the primary fluid, refrigerant vapor, which has been vaporized in the evaporator. The two materials that serve as the refrigerant—absorbent pair must meet a number of requirements however, only two have found extensive commercial use ammonia—water and water—Hthium bromide. 

Ammonia—water systems are more complex than water—Hthium bromide systems, but can be used at temperatures down to —40° C. 

Ammonia—water systems operate under moderate pressures and care must be taken to avoid leaks of the irritating and toxic ammonia (qv). Sometimes a third material with a widely different density, eg, hydrogen, is added to the cycle in order to eliminate the need for mechanical pumping. 

Water is a by-product of the amination reactions in both methods. The mixture of ammonia, water, unconverted alcohol, and amines are... 

Fig. 5. Fermentative production of amino acids (140). A, pure culture B, inoculation C, boiler D, air compressor E, air filter F, seed tank G, ammonia water for pH control H, fermenter I, sterilizer , culture media K, preparation tank L, centrifugal separator M, ion-exchange column N, crystallizing...

Fig. 2. Vapor—hquid equiUbrium of ammonia—water system. Numbers represent the weight percent of ammonia ia the Hquid (1).

United States Pharmacopeia stronger ammonia water ammonia test solution normal (1 N) aqua ammonia chemically pure technical, Bh°... 

It is equivalent to say that entropy of vaporization is a constant value for non-associating Hquids. Associating Hquids, eg, ammonia, water, methanol, and ethanol, do not obey the rule of Pictet and Trouton. Despite its simplicity, the Pictet-Trouton view of Hquid vaporization (19) is an exceUent example of the many rules of thumb that have been useful aids in engineering calculations for decades (5,7,8,9,21). However, proper appHcation requires an understanding of the physical reasoning behind each rule. 

Absorption Refrigeration Systems Two main absorption systems are used in industrial application lithium bromide-water and ammonia-water. Lithium bromide-water systems are hmited to evaporation temperatures above freezing because water is used as the refrigerant, while the refrigerant in an ammonia-water system is ammonia and consequently it can be applied for the lower-temperature requirements. 

The ammonia-water absorption system was extensively used until the fifties when the LiBr-water combination became popular. Figure 11-103 shows a simplified ammonia-water absorption cycle. The refrigerant is ammonia, and the absorbent is dilute aqueous solution of ammonia. Ammonia-water systems differ from water-lithium bromide equipment to accommodate major differences Water (here absorbent) is also volatile, so the regeneration of weak water solution to strong water solution is a fractional distillation. Different refrigerant (ammonia) causes different, much higher pressures about 1100-2100 kPa absolute in condenser. 

B. Aminolhymol.—The crude, wet nitrosothymol so obtained is worked up with a mixture of 900 cc. of 28 per cent ammonia water (sp. g. 0.90) and 1600 cc. of water the brown solution is filtered free of a little resinous matter, and hydrogen sulfide is passed into it. The brown color disappears and a white precipitate of aminothymol forms. The passage of hydrogen sulfide is continued for thirty minutes longer (Note 3), when the base is filtered and washed well with cold water, contact with air being avoided as far as possible (Note 4). 

Cellulose for chromatography is purified by sequential washing with chloroform, ethanol, water, ethanol, chloroform and acetone. More extensive purification uses aqueous ammonia, water, hydrochloric acid, water, acetone and diethyl ether, followed by drying in a vacuum. Trace metals can be removed from filter paper by washing for several hours with O.IM oxalic or citric acid, followed by repeated washing with distilled water. 

Benzamide [55-21-0] M 121,1, m 129.5", pK -2.16 (aq H2SO4), Crystd from hot water (about 5mL/g), EtOH or 1,2-dichloroethane, and air dried. Crystd from dilute aqueous ammonia, water, acetone and then benzene (using a Soxhlet extractor). Dried in an oven at 110° for 8h and stored in a desiccator over 99% H2SO4. [Bates and Hobbs y. 4m C/icm 73 2151 1951.]... 

Chelex 100 [11139-85-8], Washed successively with 2M ammonia, water, 2M nitric acid and water. Chelex 100 may develop an odour on long standing. This can be removed by heating to 80° for 2h in 3M ammonia, then washing with water. [Ashbrook J Chromatogr 105 151 1975.]... 

Mevalonic acid 5-phosphate [1189-94-2] M 228.1, pKes,(d 1.5 (PO4H2), pKEst(2) 4.4 (CO2H), pKEst(3) (P04H ). Purified by conversion to the tricyclohexylammonium salt (m 154-156°) by treatment with cyclohexylamine. Crystd from water/acetone at -15°. Alternatively, the phosphate was chromatographed by ion-exchange or paper (Whatman No 1) in a system isobutyric acid/ammonia/water (66 3 30 Rp 0.42). Stored as the cyclohexylammonium salt. 

Takuma, M., Yamada, A., Matsuo, T., and Tokita, Y., Condensation Heat Transfer Characteristics of Ammonia-Water Vapor Mixture on a Vertical Flat Surface, Proc. 10th Inti. Heat Transfer Conf, Vol.3 pp395-400, 1994. 

Chemical Designations - Synonyms Ammonia Water, Aqueous Ammonia, Household Ammonia Chemical Formula NH OH—HjO. 

A gaseous emission is to be treated for the removal of ammonia. Table 9.4 provides the stream data. Two scrubbing agents are considered for the removal of ammonia, water, Si, and an inm anic solvent, S2. The absorption of ammonia in water is coupled with the following chemical reaction ... 

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