Ammonia constant

Dissolve the perchloride of mercury in the water, with the aid of a moderate heat. Mix the solution with the ammonia, constantly stirring. Collect the precipitate (am-moniated mercury) on a Alter, and wash it well with cold distilled water until the liquid which passes through ceases to give a precipitate when dropped into a solution of silver nitrate acidulated by nitric acid. Lastly, dry the product at a temperature not exceeding 212° F. 

Prepared from ethyne and ammonia or by dehydration of ethanamide. Widely used for dissolving inorganic and organic compounds, especially when a non-aqueous polar solvent of high dielectric constant is required, e.g. for ionic reactions. 

CH3)2N]3P0. M.p. 4°C, b.p. 232"C, dielectric constant 30 at 25 C. Can be prepared from dimethylamine and phosphorus oxychloride. Used as an aprotic solvent, similar to liquid ammonia in solvent power but easier to handle. Solvent for organolithium compounds, Grignard reagents and the metals lithium, sodium and potassium (the latter metals give blue solutions). 

Similar, very detailed studies were made by Ebert [112] on water adsorbed on alumina with similar conclusions. Water adsorbed on zeolites showed a dielectric constant of only 14-21, indicating greatly reduced mobility of the water dipoles [113]. Similar results were found for ammonia adsorbed in Vycor glass [114]. Klier and Zettlemoyer [114a] have reviewed a number of aspects of the molecular structure and dynamics of water at the surface of an inorganic material. 

Microwave studies in molecular beams are usually limited to studying the ground vibrational state of the complex. For complexes made up of two molecules (as opposed to atoms), the intennolecular vibrations are usually of relatively low amplitude (though there are some notable exceptions to this, such as the ammonia dimer). Under these circumstances, the methods of classical microwave spectroscopy can be used to detennine the stmcture of the complex. The principal quantities obtained from a microwave spectmm are the rotational constants of the complex, which are conventionally designated A, B and C in decreasing order of magnitude there is one rotational constant 5 for a linear complex, two constants (A and B or B and C) for a complex that is a symmetric top and tliree constants (A, B and C) for an... 

The dissociation constant of ethanoic (acetic) acid in liquid ammonia is greater than it is in water. Suggest a reason for the difference. 

Preparation of silver maleate. Dissolve 65 g. of pure maleic acid (Section 111,143) in the calculated quantity of carefully standardised 3-5N aqueous ammonia solution in a 1-htre beaker and add, whilst stirring mechanically, a solution of 204 g. of silver nitrate in 200 ml. of water. Filter oflf the precipitated silver maleate at the pump, wash it with distilled water, and press well with the back of a large flat glass stopper. Dry in an electric oven at 50-60° to constant weight. The yield of the dry silver salt is 150 g. Store in a vacuum desiccator in the dark. 

Sulphonamides. Mix together 1 0 g. of the dry acid or 1 - 2 g. of the anhydrous salt with 2 5 g. of phosphorus pentachloride f and heat under a reflux condenser in an oil bath at 150° for 30 minutes. Cool the mixture, add 20 ml. of dry benzene, warm on a steam bath and stir the solid mass well to extract the sulphonyl chloride filter. Add the benzene solution slowly and with stirring to 10 ml. of concentrated ammonia solution. If the sulphonamide precipitates, separate it by filtration if no solid is obtained, evaporate the benzene on a steam bath. Wash the sulphonamide with a little cold water, and recrystallise from water, aqueous ethanol or ethanol to constant m.p. 

Sketch the titration curve for 50.0 mL of 5.00 X 10 M Cd + with 0.010 M EDTA at a pH of 10, and in the presence of an ammonia concentration that is held constant throughout the titration at 0.010 M. This is the same titration for which we previously calculated the titration curve (Table 9.15 and figure 9.27). 

Unsubstituted Amides. The most widely used synthetic route for primary amides is the reaction of fatty acid with anhydrous ammonia (11). Fatty acid and ammonia are allowed to react at approximately 200°C for 10 to 12 h under a constant vent of excess ammonia and water by-product. A pressure of 345—690 kPa (50—100 psi) is maintained by the addition of ammonia while the venting of water faciUtates the completion of the reaction. 

Essential for synthesis considerations is the abiUty to determine the amount of ammonia present ia an equiUbrium mixture at various temperatures and pressures. ReHable data on equiUbrium mixtures for pressures ranging from 1,000 to 101,000 kPa (10 —1000 atm) were developed early on (6—8) and resulted ia the determination of the reaction equiUbrium constant (9). Experimental data iadicates that is dependent not only on temperature and pressure, but also upon the ratio of hydrogen and nitrogen present. Table 3 fists values for the ammonia equilibrium concentration calculated for a feed usiag a 3 1 hydrogen to nitrogen ratio and either 0 or 10% iaerts (10). 

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. 

Dry air is blown through the solution to remove the excess of ammonia, and the solution is then dissolved in its own volume of absolute alcohol. A sample of this solution is titrated with standard oxalic acid, litmus being used as an outside indicator (Note 3). The amount of oxalic acid (Note 4) necessary to form the acid salt is placed in a large evaporating dish and dissolved in 4 1. of 95 per cent alcohol. The amine solution is then slowly run into the acid with constant stirring. During the addition of the last half of the amine solution, the container must be cooled in order to avoid the formation of the neutral oxalate,... 

Another method for removing O2 is to pass the nitrogen through a long tightly packed column of Cu turnings, the surface of which is constantly renewed by scrubbing it with ammonia (sg 0.880) soln. The gas is then... 

In some materials and environments, cracks grow steadily under a constant stress intensity K which is much less than (Fig. 23.8). This is obviously dangerous a structure which is safe when built can become unsafe with time. Examples are brass in ammonia, mild steel in caustic soda, and some A1 and Ti alloys in salt water. 

Ammonia is released at a constant rate (loading or unloading) for time T. 

The released ammonia forms a pool of refrigerated liquid which evaporates by heat transfer from the soil. A constant mass value was assumed for the evaporation rate and a heavier-than-air gas dispersion model was used. 

The ethereal solution of crude quinidine and cinchonidine, obtained as described under cinchonine, is shaken with dilute hydrochloric acid, the excess acid neutralised with ammonia and sodium potassium tartrate added. The base is recovered from the precipitated tartrate by dissolving the latter in dilute acid and pouring the filtered solution in a thin stream, slowly and with constant stirring, into excess of ammonia solution. The crude alkaloid is converted into the neutral sulphate, and this recrystallised... 

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