Salt dissolvers

Liquid ammonia, like water, is only a poor conductor of electricity. Ammonium salts dissolved in water behave as acids giving the ion NH4, whilst amides which give the ion NHj behave as bases. Thus the reaction ... 

We have already seen that in the aquo-complex which is usually formed when a simple transition metal salt dissolves in water, the... 

When a copper(II) salt dissolves in water, the complex aquo-ion [Cu(H2p)6P is formed this has a distorted octahedral (tetragonal) structure, with four near water molecules in a square plane around the copper and two far water molecules, one above and one below this plane. Addition of excess ammonia replaces only the four planar water molecules, to give the deep blue complex [Cu(NH3)4(H20)2] (often written as [Cu(NHj)4] for simplicity). TTo obtain [Cu(NH3)6], water must be absent, and an anhydrous copper(II) salt must be treated with liquid ammonia. 

For this preparation, it is particularly necessary that the sodium acetate should be free from traces of water. The anhydrous material can be prepared by gently heating the hydrated salt (CHsCOONa,3HjO) in an esaporating-basin over a small Bunsen flame. The salt dissolves in its water of ciystallisation and resolidifies as this water is driven off further heating then causes the anhydrous material to melt. Stir the molten anhydrous material to avoid charring, and then allow it to cool in a desiccator. Powder the cold material rapidly in a mortar, and bottle without delay. 

Below -30°C salts precipitate from the solution and the reaction stops, probably because the pieces of lithium are covered with salt, [f the temperature is increased, the salts dissolve and the gloss on the lithium re-appears. 

In spite of being ionic many quaternary ammonium salts dissolve m nonpolar media The four alkyl groups attached to nitrogen shield its positive charge and impart lipophilic character to the tetraalkylammonium ion The following two quaternary ammonium salts for example are soluble m solvents of low polarity such as benzene decane and halo genated hydrocarbons... 

Iron (III) chloride hexahydrate [10025-77-17, FeCl36H2 0, is a brown-yeUow to orange material that crystallizes from a solution of iron or iron salt dissolved ia hydrochloric acid that coataias an oxidant such as Cfy or nitric acid. The monoclinic crystals contain the complex salt... 

Physical Properties. Sulfuryl chloride [7791-25-5] SO2CI2, is a colorless to light yellow Hquid with a pungent odor. Physical and thermodynamic properties are Hsted ia Table 7. Sulfuryl chloride dissolves sulfur dioxide, bromine, iodine, and ferric chloride. Various quaternary alkyl ammonium salts dissolve ia sulfuryl chloride to produce highly conductive solutions. Sulfuryl chloride is miscible with acetic acid and ether but not with hexane (193,194). 

Naphthol AS Coupling Components. Naphthol AS components are the aryhdes of either o-hydroxyarylcarboxycHc acids or acylacetic acids. They are free of sulfo and carboxyl groups, but form salts with bases these salts dissolve in water to give colloidal solutions, which couple with diazo components to form colored pigments. The whole class derives from the anilide of 3-hydroxy-2-naphthoic acid [92-70-6] Naphthol AS (85) (Cl Azoic Coupling Component 2). 

In metallic form, barium is very reactive, reacting readily with water to release hydrogen. In aqueous solution it is present as an ion with a +2 charge. Barium acetate, chloride, hydroxide, and nitrate are water-soluble, whereas barium arsenate, chromate, duoride, oxalate, and sulfate are not. Most water-insoluble barium salts dissolve in dilute acids barium sulfate, however, requkes strong sulfuric acid. 

The rate of hydrolysis of cellulose acetate can be monitored by removing samples at intervals during hydrolysis and determining the solubiUty of the hydrolyzed acetate. When the desired DS is reached, the hydrolysis is stopped by neutralizing the catalyst with magnesium, calcium, or sodium salts dissolved in aqueous acetic acid. 

L-Tyrosine [60-18-4] M 181.2, m 290-295 (dec), [aj -10.0 (5M HCl), pK 2.18 (CO2H), pK2 9.21 (OH), pK 3 10.47 (NH2). Likely impurities are L-cysteine and the ammonium salt. Dissolved in dilute ammonia, then crystd by adding dilute acetic acid to pH 5. Also crystd from water or EtOH/water, and dried at room temperature under vacuum over P2O5. 

In a 500-ml. round-bottomed flask equipped with a reflux condenser and a magnetic stirrer (Note 6) are placed 150 ml. of methanol, 150 ml. of 6N hydrochloric acid, and the total yield of 4,4 -bis(acetamido)azobenzene. The mixture is heated under reflux for 1.5 hours. The reaction mixture is cooled and the violet solid collected on a Buchner funnel (Note 7). The damp product is suspended in 500 ml. of water in a 1-1. beaker equipped with a stirrer, and the mixture is slowly neutralized by the addition of 2.5N sodium hydroxide. In the course of the neutralization, the salt dissolves and the free base separates. The 4,4 -diaminoazo-benzene is collected on a Buchner funnel, washed with water, and dried under reduced pressure. The yield of yellow product, m.p. 238-241° (dec.),is ll-12g. The over-all yield from/ -amino-acetanilide is 52-56%. 

Withsomesaltsthevolumeofthesolutionexpandsastheirconcentrationincreases thisleads to a value of the constant y. This tells us mathematically that as the salt dissolves into the... 

Preparation. The mother liquors from strychnine manufacture are concentrated and the alkaloids precipitated as neutral oxalates. The precipitate is dried and extracted with dry alcohol in which the strychnine salt is the more soluble. The less soluble salt dissolved in water is decolorised with charcoal, the alkaloid regenerated with ammonia and purified by crystallisation as the sulphate. According to Saunders, pure brucine may be obtained by slow crystallisation from a solution of the pure hydrochloride in alcoholic ammonia. A method of separation depending on the greater solubility in water of strychnine hydriodide was employed by Shenstone, whilst others have made use of the sparing solubility of strychnine chromate for the removal of small quantities of this alkaloid from brucine. For a large scale process see Schwyzer. ... 

It is evident therefore that Fe salts dissolved in water produce highly acidic solutions and the simple, pale-violet, hexaaquo ion only predominates if further acid is added to give pH - 0. At somewhat higher values of pH the solution becomes yellow due to the appearance of the above hydrolysed species and if the pH is raised above 2-3, further condensation occurs, colloidal gels begin to form, and eventually a... 

This is the basis of the very sensitive Fehling s test for sugars and other reducing agents. A solution of a copper(H) salt dissolved in alkaline tartrate solution is added to the substance in question. If this is a reducing agent then a characteristic red precipitate is produced. 

Diels-Alder reactions Neutral ionic liquids have been found to be excellent solvents for the Diels-Alder reaction. The first example of a Diels-Alder reaction in an ionic liquid was the reaction of methyl acrylate with cyclopentadiene in [EtNH3][N03] [40], in which significant rate enhancement was observed. Howarth et al. investigated the role of chiral imidazolium chloride and trifluoroacetate salts (dissolved in dichloromethane) in the Diels-Alder reactions between cyclopentadiene and either crotonaldehyde or methacroline [41]. It should be noted that this paper describes one of the first examples of a chiral cationic ionic liquid being used in synthesis (Scheme 5.1-17). The enantioselectivity was found to be < 5 % in this reaction for both the endo (10 %) and the exo (90 %) isomers. 

Electrolyte a substance, liquid or solid, which conducts electrical current by movement of ions (not of electrons). In corrosion science, an electrolyte is usually a liquid solution of salts dissolved in a solvent, or a molten salt. The term also applies to polymers and ceramics which are ionically conductive. 

Appreciable amounts of organic salts dissolve during the extraction of the sugar and interfere seriously with the crystallization of the latter. Most of the salts are precipitated by addition of 95 per cent ethyl alcohol, leaving the sugar in solution. 

Water is a very poor conductor of electricity. Yet when sodium chloride dissolves in water, the solution conducts readily. The dissolved sodium chloride must be responsible. How does the dissolved salt permit charge to move through the liquid One possibility is that when salt dissolves in water, particles with electric charge are produced. The movement of these charged particles through the solution accounts for the current. Salt has the formula, NaCl—for every sodium atom there is one chlorine atom. Chemists have... 

If x is the degree of hydrolysis of 1 mole of the salt dissolved in V litres of solution, then the individual concentrations are ... 

Procedure. Weigh out accurately about 3.0 g of the salt, dissolve it in water, and make up to 250 mL in a graduated flask. Shake well. Pipette 50.0 mL of this solution into a 250 mL conical flask, add 1 g potassium iodide (or 10 mL of a 10 per cent solution) (Note 1), and titrate the liberated iodine with standard... 

Bismuth. 25.0 mL bismuth ion solution + solid hexamine to pH about 4.6 the precipitate of basic bismuth salt dissolves as the EDTA solution is added but the titration is slow. 

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