Ammonia solutions of sodium

Reactions in liquid ammonia (cf. Chapter 3, Section III) require a certain amount of care, since the solvent is low boiling (—33 ) and its fumes are noxious. Nevertheless, with reasonable caution, the preparation of an ammonia solution of sodium acetylide can be carried out as described. The reagent so prepared can then be directly used for displacements on alkyl halides or for additions to suitable carbonyl compounds. Examples of both reactions are given. 

Using the relevant tables, find the solubilities of the salts that can form in an ammonia solution of sodium chloride saturated with carbon dioxide. Explain the sequence of the processes occurring in this reaction mixture. Recrystallize the product from warm water (about 50 G). 

The free radical NH4 has been isolated only in the form of its amalgam (Davy, 1811) which precipitates the more noble metals, such as copper, cadmium, and zinc, from their solutions. Solutions of ammonium in liquid ammonia are blue and usually exhibit properties similar to liquid ammonia solutions of sodium and potassium. 

Lead dissolves in liquid ammonia solutions of sodium giving a highly coloured liquid. The formation of pol) plumbides has been demonstrated by electrometrically titrating a solution of sodium in ammonia with one of lead iodide in ammonia the compounds formed are Na Pb and Na Pbg. The electrolysis of such a solution releases Na at the cathode and Pb at the anode. Evaporation gives [Na(NH3) ]4Pbg which loses NHg to leave pyrophoric Na Pbg. These compounds seem to possess a character between that of a true valency compound and an intermediate phase (Zintl, 1929),... 

The potentials at which electrons are generated in a liquid ammonia solution of sodium salts are also more positive than the reversible potential of the sodium electrode but in this system too the authors of Refs. and succeeded in realizing a reversible sodium electrode consisting of metallic sodium covered with a layer of beta-aluminate. The conductivity of the latter is due to sodium ions. 

Rapid and quantitative polymerization of 4-vinyl-pyridine in liquid ammonia solution of sodium at - 50 °C was reported by Laurin and Parravano79). A high molecular weight and apparently living polymer was obtained in less than a minute. 

The first attempts (5) to reduce metal salts with sodium at low temperatures were made by researchers working with solutions of sodium in liquid ammonia. In 1925 Kraus and Kurtz (7) showed that liquid ammonia solutions of sodium could be used to reduce halides of metals that form alloys with sodium. Operating at temperatures below the boiling point of the ammonia solutions they succeeded in reducing the halides of mercury, cadmium, zinc, tin, lead, antimony, bismuth, and thallium, and, by using an excess of sodium, concomitantly produced sodium alloys of these metals. Kraus and Kurtz postulated mechanisms for the reactions and showed that many of the alloys formed were unstable in liquid ammonia— i.e., they disproportionated into free sodium and lower sodium alloys. 

If this conclusion is valid, a sodium dispersion should approach the degree of reactivity toward metal halides that is shown by sodium addition compoimds or liquid ammonia solutions of sodium. 

Nitrogen oxide does show some ability to gain an electron and when passed into a solution of sodium in liquid ammonia, the... 

Dissolve 15-0 g. of A.R. barium nitrate and 130 g. of A.R. cupric nitrate trihydrate in 450 ml. of water at 80°. Prepare a solution of sodium chromate by dissolving 89 g. of recrystallised sodium dichromate dihydrate in 200 ml. of water and adding 112 5 ml. of cone, ammonia solution (sp. gr. 0-90). Add the warm solution (80°) of nitrates in a thin stream, with stirring, to the sodium chromate solution (at 25°). Collect the orange precipitate by suction Bltration, wash it with two 50 ml. portions of 5fiter, drain well, and dry at 75-80° for 12 hours powder finely. 

Solutions of sodium acetylide (HC=CNa) may be prepared by adding sodium amide (NaNH2) to acetylene m liquid ammonia as the solvent Terminal alkynes react similarly to give species of the type RC=CNa... 

Acetaldehyde can be isolated and identified by the characteristic melting points of the crystalline compounds formed with hydrazines, semicarbazides, etc these derivatives of aldehydes can be separated by paper and column chromatography (104,113). Acetaldehyde has been separated quantitatively from other carbonyl compounds on an ion-exchange resin in the bisulfite form the aldehyde is then eluted from the column with a solution of sodium chloride (114). In larger quantities, acetaldehyde may be isolated by passing the vapor into ether, then saturating with dry ammonia acetaldehyde—ammonia crystallizes from the solution. Reactions with bisulfite, hydrazines, oximes, semicarb azides, and 5,5-dimethyl-1,3-cyclohexanedione [126-81 -8] (dimedone) have also been used to isolate acetaldehyde from various solutions. 

In addition, there are other methods of manufacture of cryoHte from low fluorine value sources, eg, the effluent gases from phosphate plants or from low grade fluorspar. In the former case, making use of the fluorosiHcic acid, the siHca is separated by precipitation with ammonia, and the ammonium fluoride solution is added to a solution of sodium sulfate and aluminum sulfate at 60—90°C to precipitate cryoHte (26,27) ... 

Articles fabricated from FEP resins can be made bondable by surface treatment with a solution of sodium in Hquid ammonia, or naphthalenyl sodium in tetrahydrofuran (64) to faciUtate subsequent wetting. Exposing the surface to corona discharge (65) or amines at elevated temperatures in an oxidizing atmosphere (66) also makes the resins bondable. Some of the more recent work is described in References 67—69. 

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). 

Iron, cobalt, and nickel catalyze this reaction. The rate depends on temperature and sodium concentration. At —33.5°C, 0.251 kg sodium is soluble in 1 kg ammonia. Concentrated solutions of sodium in ammonia separate into two Hquid phases when cooled below the consolute temperature of —41.6°C. The compositions of the phases depend on the temperature. At the peak of the conjugate solutions curve, the composition is 4.15 atom % sodium. The density decreases with increasing concentration of sodium. Thus, in the two-phase region the dilute bottom phase, low in sodium concentration, has a deep-blue color the light top phase, high in sodium concentration, has a metallic bronze appearance (9—13). 

Arsine is formed when any inorganic arsenic-bearing material is brought in contact with zinc and sulfuric acid. The arsenides of the electropositive metals are decomposed with the formation of arsine by water or acid. Calcium arsenide [12255-53-7] Ca2As2, treated with water gives a 14% yield of arsine. Better yields (60—90%) are obtained by decomposing a solution of sodium arsenide [12044-25-6] Na As, in Hquid ammonia with ammonium bromide (14,15). Arsine may be accidentally formed by the reaction of arsenic impurities in commercial acids stored in metal tanks, so that a test should be made for... 

The chemical resistance of PTFE is exceptional. There are no solvents and it is attacked at room temperature only by molten alkali metals and in some cases by fluorine. Treatment with a solution of sodium metal in liquid ammonia will sufficiently alter the surface of a PTFE sample to enable it to be cemented to other materials using epoxide resin adhesives. 

A solution of sodium amide (0.226 mole) in liquid ammonia is prepared in a 1-1. three-necked tlask equipped with a condenser, a ball-scaled mechanical stirrer, and a dro ii)ing funnel. Commercial anhydrous lii(uid ammonia (500 ml.) is introduced from... 

Note If the spray solution or a nonbasic dipping solution is employed for detection then it is advisable to spray afterwards with a 10% aqueous solution of sodium carbonate or a 2% solution of borax in ethanol — water (1 + 1). It is often possible to achieve the required basicity by placing the chromatogram in a twin-trough chamber one of whose troughs contains 5 ml 25% ammonia. This is not suitable for the Chiralplate (Macherey-Nagel) because in this case the plate background acquires a dark violet coloration. 

The most effective preparative routes to hydrazine are still based on the process introduced by F. Raschig in 1907 this involves the reaction of ammonia with an alkaline solution of sodium hypochlorite in the presence of gelatin or glue. The overall reaction can be written as... 

Preparation of J-Methy/ Lumilysergic Acid 8-Methyl Ester-10-Methyt Ether into a suspension of 10 grams of 1-methyi-iumiiysergic acid in 600 cc of absoiute methanoi a stream of anhydrous hydrogen chloride is bubbied for 1.5 hours with strong cooiing. The stream of hydrogen chloride is stopped and the mixture is aiiowed to stand for 30 minutes at 0°C, and is evaporated in vacuo to dryness. The residue is taken up with ice-cooied water made aikaiine with concentrated ammonia and extracted with chioroform. The combined chioro-form extracts are washed first with a 5% aqueous solution of sodium bicarbonate, then with water, and are thereafter dried over anhydrous sodium sulfate and finally evaporated in vacuo to dryness. 

In view of the lack of a simple valence relation between the atoms, complex atom-groups may be formed in sodium cadmide in a way similar to the formation of Pt>2- ions in a solution of sodium plumbide, NaPb2, in liquid ammonia,9 preventing a simplicity of structure. 

In 0-level qualitative analysis, unknown cations are identified by reacting them with aqueous sodium hydroxide and/or aqueous ammonia. For example, zinc salt solutions react with aqueous sodium hydroxide to form a white precipitate, zinc hydroxide, which in turn will react with excess aqueous sodium hydroxide to form a colourless solution of sodium zincate, a complex salt. However, 25% of the 915 students thought that when sodium hydroxide solution was added to a solution of a zinc salt, a displacement reaction resulted leading to the formation of a precipitate... 

Freeder, B. G. et al., J. Loss Prev. Process Ind., 1988, 1, 164-168 Accidental contamination of a 90 kg cylinder of ethylene oxide with a little sodium hydroxide solution led to explosive failure of the cylinder over 8 hours later [1], Based on later studies of the kinetics and heat release of the poly condensation reaction, it was estimated that after 8 hours and 1 min, some 12.7% of the oxide had condensed with an increase in temperature from 20 to 100°C. At this point the heat release rate was calculated to be 2.1 MJ/min, and 100 s later the temperature and heat release rate would be 160° and 1.67 MJ/s respectively, with 28% condensation. Complete reaction would have been attained some 16 s later at a temperature of 700°C [2], Precautions designed to prevent explosive polymerisation of ethylene oxide are discussed, including rigid exclusion of acids covalent halides, such as aluminium chloride, iron(III) chloride, tin(IV) chloride basic materials like alkali hydroxides, ammonia, amines, metallic potassium and catalytically active solids such as aluminium oxide, iron oxide, or rust [1] A comparative study of the runaway exothermic polymerisation of ethylene oxide and of propylene oxide by 10 wt% of solutions of sodium hydroxide of various concentrations has been done using ARC. Results below show onset temperatures/corrected adiabatic exotherm/maximum pressure attained and heat of polymerisation for the least (0.125 M) and most (1 M) concentrated alkali solutions used as catalysts. 

Liquid household bleach is generally a 5% solution of sodium hypochlorite (NaOCl). Ammonia cleansers—including general household cleansers, wax removers, glass and window cleaners, and oven cleaners — are aqueous solutions of 5-10% ammonia, NH3. Mixing bleach with cleansers containing ammonia leads to the formation of a family of potentially toxic compounds known as chloramines. These toxic gases have acrid fumes that can bum mucous membranes. Scented bleaches can mask one s natural ability to detect these harmful fumes. 

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