Ammonia acidity and

The methyl 4,6-0-benzylidene-2, S-dideoxy-S-C-nitro-iS-D-er /i/iro- and -threo-hex-2-enosides can be prepared by a facile elimination of acetic acid from the appropriate 2-0-acetyl-3-deoxy-3-C-nitro compounds they add hydrogen, ammonia, acids, and alcohols to give pyranoside products having deoxy, aminodeoxy, acyloxy, and alkoxy groupings at C-2 A wide variety of 3-amino-3-deoxy sugar derivatives may therefore be synthesized from these unsaturated compounds. 

Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic Chemicals (Ammonia, Acids and Fertilisers) LVIC-AAF... 

Plant solutions are normally prepared by dissolving metallic copper in a mixture of ammonia, acid, and water. The use of distilled water is desirable since chlorides or sulfates, which may be introduced with less-pure water sources, can result in corrosion. It is necessary to blow air into the dissolver to oxidize the copper to the cupric state, and the cupric copper that is formed is capable of dissolving additional elemental copper by oxidizing it to the soluble cuprous form. The reaction is also of value as a means of controlling the cupric/cuprous ion ratio in the solution as it is made. Careful control of ammonia and acid concentrations is also required. An excess of acid relative to aimnonia can cause the solution to become corrosive, while insufficient ammonia or acid can result in the precipitation of copper compounds. 

European Commission, 2007. Integrated pollution prevention and control reference document on best available techniques for the manufacture of large volume inorganic chemicals— ammonia, acids and fertilisers. Retrieved from http //eippcb.jrc.es/reference/BREF/lvic bref 0907.pdf (accessed 05.10.12). 

Catalytic gas-phase reactions play an important role in many bulk chemical processes, such as in the production of methanol, ammonia, sulfuric acid, and nitric acid. In most processes, the effective area of the catalyst is critically important. Since these reactions take place at surfaces through processes of adsorption and desorption, any alteration of surface area naturally causes a change in the rate of reaction. Industrial catalysts are usually supported on porous materials, since this results in a much larger active area per unit of reactor volume. 

They are formed by heating dibasic acids or their anhydrides with ammonia. The hydrogen atom of the NH group is acidic and can be replaced by a metal. Mild hydrolysis breaks the ring to give the half amide of the acid. See succinimide and phthalimide. 

A new dimension to acid-base systems has been developed with the use of zeolites. As illustrated in Fig. XVIII-21, the alumino-silicate faujasite has an open structure of interconnected cavities. By exchanging for alkali metal (or NH4 and then driving off ammonia), acid zeolites can be obtained whose acidity is comparable to that of sulfuric acid and having excellent catalytic properties (see Section XVIII-9D). Using spectral shifts, zeolites can be put on a relative acidity scale [195]. An important added feature is that the size of the channels and cavities, which can be controlled, gives selectivity in that only... 

When we use any substance as a solvent for a protonic acid, the acidic and basic species produced by dissociation of the solvent molecules determine the limits of acidity or basicity in that solvent. Thus, in water, we cannot have any substance or species more basic than OH or more acidic than H30 in liquid ammonia, the limiting basic entity is NHf, the acidic is NH4. Many common inorganic acids, for example HCl, HNO3, H2SO4 are all equally strong in water because their strengths are levelled to that of the solvent species Only by putting them into a more acidic... 

Uses of ammonia and ammonium compounds. Most of the ammonia produced is used in the manufaeture of nitrogenous fertilisers such as ammonium sulphate. Other uses include nitric acid and synthetic fibre and plastic manufacture. 

Ammonia may be estimated by dissolving the gas in a known volume of standard acid and then back-titrating the excess acid. In a method widely used for the determination of basic nitrogen in organic substances (the Kjeldahl method), the nitrogenous material is converted into ammonium sulphate by heating with concentrated sulphuric acid. The ammonia is then driven off by the action of alkali and absorbed in standard acid. 

By the evolution of ammonia with Devarda s alloy in alkaline solution in absence of ammonium ions this is used quantitatively, the ammonia being absorbed in excess standard acid and the excess acid back-titrated. 

Oxamide differs from most aliphatic acid amides in being almost insoluble in water, and therefore can be readily prepared from the diethyl ester by Method 2(a). Place a mixture of 5 ml. of concentrated [d o-88o) ammonia solution and 5 ml. of water in a 25 ml. conical flask, for which a welTfitting cork is available. (The large excess of... 

Hydrolysis of Benzamide. When acid amides are hydrolysed, the corresponding acid and ammonia are formed. Consequently the hydrolysis, which is extremely slow with water alone, is hastened con-... 

Hydrolysis of Acetonitrile. Nitriles, like acid amides, undergo hydrolysis to give the corresponding carboxylic acid and ammonia. Consequently... 

A certain amount of hydrolysis of the original acetamide to acid and ammonia always occurs, and the final amine always contains traces of ammonia. This is separated by extracting the mixed anhydrous hydrochlorides with absolute ethanol, which dissolves the amine hydrochloride but not the ammonium chloride filtration of the hot ethanolic extract removes the ammonium chloride, whilst the amine hydrochloride crystallises readily from the filtrate on cooling. 

To prepare the hydrochloride, add about i g. of aminoazobenzene to 200 ml. of dilute hydrochloric acid and boil until nearly all the solid material has dissolved. Filter hot and allow to cool slowly. Aminoazobenzene hydrochloride separates as beautiful steel-blue crystals filter and dry. If a small quantity of the powdered hydrochloride is moistened with water and a few drops of ammonia added, the blue hydrochloride is converted back to the yellowish-brown base. 

Gently warm a mixture of 32 g. (32 ml.) of ethyl acetoacetate and 10 g. of aldehyde-ammonia in a 400 ml. beaker by direct heating on a gauze, stirring the mixture carefully with a thermometer. As soon as the reaction starts, remove the heating, and replace it when the reaction slackens, but do not allow the temperature of the mixture to exceed 100-no the reaction is rapidly completed. Add to the mixture about twice its volume of 2A -hydrochloric acid, and stir the mass until the deposit either becomes solid or forms a thick paste, according to the quality of the aldehyde-ammonia employed. Decant the aqueous acid layer, repeat the extraction of the deposit with more acid, and again decant the acid, or filter off the deposit if it is solid. Transfer the deposit to a conical flask and recrystallise it twice from ethanol (or methylated spirit) diluted with an equal volume of water. The i,4-dihydro-collidine-3,5-dicarboxylic diethyl ester (I) is obtained as colourless crystals, m.p. 130-131°. Yield 12 5 g,... 

Colorations or coloured precipitates are frequently given by the reaction of ferric chloride solution with.(i) solutions of neutral salts of acids, (ii) phenols and many of their derivatives, (iii) a few amines. If a free acid is under investigation it must first be neutralised as follows Place about 01 g. of the acid in a boiling-tube and add a slight excess of ammonia solution, i,e., until the solution is just alkaline to litmus-paper. Add a piece of unglazed porcelain and boil until the odour of ammonia is completely removed, and then cool. To the solution so obtained add a few drops of the "neutralised ferric chloride solution. Perform this test with the following acids and note the result ... 

Since the silver salts of the carboxylic acids are usually soluble in dilute nitric acid, they must be prepared by treating an aqueous solution of a neutral salt of the acid (and not the free acid itself) with silver nitrate solution. It is not practicable to attempt to neutralise the acid with sodium or potassium hydroxide solution, because the least excess of alkali would subsequently cause the white silver salt to be contaminated with brown silver oxide. The general method used therefore to obtain a neutral solution j to dissolve the acid in a small excess of ammonia solution, and then to boil the solution until all free... 

Alternatively, to prevent undue hydrolysis, make the solution just alkaline to phcnolphthalein with sodium hydroxide, then just acid with dilute nitric acid, and finally, add a slight excess of ammonia. 

In aqueous solution at 100° the change is reversible and equilibrium is reached when 95 per cent, of the ammonium cyanate has changed into urea. Urea is less soluble in water than is ammonium sulphate, hence if the solution is evaporated, urea commences to separate, the equilibrium is disturbed, more ammonium cyanate is converted into urea to maintain the equilibrium and evfflitually the change into urea becomes almost complete. The urea is isolated from the residue by extraction with boiling methyl or ethyl alcohol. The mechanism of the reaction which is generally accepted involves the dissociation of the ammonium cyanate into ammonia and cyanic acid, and the addition of ammonia to the latter ... 

Picrates, Many aromatic hydrocarbons (and other classes of organic compounds) form molecular compounds with picric acid, for example, naphthalene picrate CioHg.CgH2(N02)30H. Some picrates, e.g., anthracene picrate, are so unstable as to be decomposed by many, particularly hydroxylic, solvents they therefore cannot be easily recrystaUised. Their preparation may be accomplished in such non-hydroxylic solvents as chloroform, benzene or ether. The picrates of hydrocarbons can be readily separated into their constituents by warming with dilute ammonia solution and filtering (if the hydrocarbon is a solid) through a moist filter paper. The filtrate contains the picric acid as the ammonium salt, and the hydrocarbon is left on the filter paper. 

Dissolve 1 0 g. of the compound in 5 ml. of dry chloroform in a dry test-tuhe, cool to 0°, and add dropwise 5g. (2-8 ml.) of redistilled chloro-sulphonic acid. When the evolution of hydrogen chloride subsides, allow the reaction mixture to stand at room temperature for 20 minutes. Pour the contents of the test-tube cautiously on to 25 g. of crushed ice contained in a small beaker. Separate the chloroform layer and wash it with a httle cold water. Add the chloroform layer, with stirring, to 10 ml. of concentrated ammonia solution. After 10 minutes, evaporate the chloroform on a water bath, cool the residue and treat it with 5 ml. of 10 per cent, sodium hydroxide solution the sulphonamide dissolves as the sodium derivative, RO.CgH4.SO,NHNa. Filter the solution to remove any insoluble matter (sulphone, etc.), acidify the filtrate with dilute hydrochloric acid, and cool in ice water. Collect the sulphonamide and recrystallise it from dilute alcohol. 

---