By Electrolysis

At- the conclusion of the electrolysis the electrolyte is decanted, and the amalgam is washed several times with distilled water, with alcohol, and finally with ether. The amalgam is preserved in a bottle with a tightly fitting glass stopper. 

Results of three typical runs are given in Table I. The product is heterogeneous in character and consists of crystals of solid amalgam mixed with the dilute liquid amalgam. For analysis, samples were removed immediately after electrolysis and allowed to decompose for a period of five to six days in contact with air. The mass 

The procedure described here consists in adding powdered sodium amalgam to a saturated aqueous solution of barium chloride and stirring until the reaction is practically complete. 

The sodium amalgam powder containing 2 to 2.5 per cent sodium by weight (synthesis 4) is added to an excess of a saturated solution of barium chloride. By means of a flattened stirring rod the reaction product is gradually worked from a powdery into a pasty, semisolid mass. If it is desirable to reduce to an absolute minimum the amount of sodium remaining in the amalgam, the product may be stirred further with fresh barium chloride solution. 

Results of a typical preparation are presented in Table II. In this experiment, a sodium amalgam containing 1.97 per cent sodium was added to a saturated solution of barium chloride. Samples were taken at various intervals and analyzed for their barium and sodium content. 

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Colourless crystals m.p. I25°C, soluble in water and alcohol. In aqueous solution forms equilibrium with its lactones. Gluconic acid is made by the oxidation of glucose by halogens, by electrolysis, by various moulds or by bacteria of the Acetobacter groups. 

Nitroxylic acid, HiNO . Yellow NajNOa formed by electrolysis NaN02 in NHj. Structure unknown free acid unknown. Nitramide, H2NNO2. A weak acid. 

H0S(0)200S(0)20H. Dibasic acid formed as salts by electrolysis of sulphates at low temperatures and high current density. The acid and persulphates are strong oxidizing agents ( "[S20a] to S04 -t-2 01 volts in acid) but the reactions are often slow. Compare permonosulphuric acid. 

The existence of the hydride ion is shown by electrolysis of the fused salt when hydrogen is evolved at the anode. If calcium hydride is dissolved in another fused salt as solvent, the amount of hydrogen evolved at the anode on electrolysis is 1 g for each Faraday of current (mole of electrons) passed, as required by the laws of electrolysis. 

The general characteristics of all these elements generally preclude their extraction by any method involving aqueous solution. For the lighter, less volatile metals (Li, Na, Be, Mg, Ca) electrolysis of a fused salt (usually the chloride), or of a mixture of salts, is used. The heavier, more volatile metals in each group can all be similarly obtained by electrolysis, but it is usually more convenient to take advantage of their volatility and obtain them from their oxides or chlorides by displacement, i.e. by general reactions such as... 

Sodium hydroxide is manufactured by electrolysis of concentrated aqueous sodium chloride the other product of the electrolysis, chlorine, is equally important and hence separation of anode and cathode products is necessary. This is achieved either by a diaphragm (for example in the Hooker electrolytic cell) or by using a mercury cathode which takes up the sodium formed at the cathode as an amalgam (the Kellner-Solvay ceW). The amalgam, after removal from the electrolyte cell, is treated with water to give sodium hydroxide and mercury. The mercury cell is more costly to operate but gives a purer product. 

Each of these elements can be extracted by reduction of the respective oxide at high temperature, using either carbon or hydrogen or by electrolysis of an aqueous solution of a salt of the required element. 

Graphite reacts with alkali metals, for example potassium, to form compounds which are non-stoichiometric but which all have limiting compositions (for example K C) in these, the alkaU metal atoms are intercalated between the layers of carbon atoms. In the preparation of fluorine by electrolysis of a molten fluoride with graphite electrodes the solid compound (CF) polycarbon fluoride is formed, with fluorine on each carbon atom, causing puckering of the rings. 

Fluorine cannot be prepared directly by chemical methods. It is prepared in the laboratory and on an industrial scale by electrolysis. Two methods are employed (a) using fused potassium hydrogen-fluoride, KHFj, ill a cell heated electrically to 520-570 K or (b) using fused electrolyte, of composition KF HF = 1 2, in a cell at 340-370 K which can be electrically or steam heated. Moissan, who first isolated fluorine in 1886, used a method very similar to (b) and it is this process which is commonly used in the laboratory and on an industrial scale today. There have been many cell designs but the cell is usually made from steel, or a copper-nickel alloy ( Monel metal). Steel or copper cathodes and specially made amorphous carbon anodes (to minimise attack by fluorine) are used. Hydrogen is formed at the cathode and fluorine at the anode, and the hydrogen fluoride content of the fused electrolyte is maintained by passing in... 

Manganese is the third most abundant transition metal, and is widely distributed in the earth s crust. The most important ore is pyrolusite, manganese(IV) oxide. Reduction of this ore by heating with aluminium gives an explosive reaction, and the oxide Mn304 must be used to obtain the metal. The latter is purified by distillation in vacuo just above its melting point (1517 K) the pure metal can also he obtained by electrolysis of aqueous manganese(II) sulphate. 

Pure iron is prepared by reduction of iron(II) oxide with hydrogen, or by electrolysis of an iron(II)-containing aqueous solution. It is a fairly soft metal, existing in different form according to temperature ... 

English, soda Medieval Latin, sodanum, headache remedy) Long recognized in compounds, sodium was first isolated by Davy in 1807 by electrolysis of caustic soda. 

The metal is now principally obtained in the U.S. by electrolysis of fused magnesium chloride derived from brines, wells, and sea water. 

English, potash - pot ashes L.. kalium, Arab qali, alkali) Discovered in 1807 by Davy, who obtained it from caushc potash (KOH) this was the first metal isolated by electrolysis. 

Potassium is never found free in nature, but is obtained by electrolysis of the hydroxide, much in the same manner as prepared by Davy. Thermal methods also are commonly used to produce potassium (such as by reduction of potassium compounds with CaC2, C, Si, or Na). 

The metal has a silvery color, is rather hard, and is prepared by electrolysis of the fused chloride to which calcium fluoride is added to lower the melting point. 

Large copper ore deposits are found in the U.S., Chile, Zambia, Zaire, Peru, and Canada. The most important copper ores are the sulfides, the oxides, and carbonates. From these, copper is obtained by smelting, leaching, and by electrolysis. 

L. Gallia, France also from Latin, gallus, a translation of Lecoq, a cock) Predicted and described by Mendeleev as ekaaluminum, and discovered spectroscopically by Lecoq de Boisbaudran in 1875, who in the same year obtained the free metal by electrolysis of a solution of the hydroxide in KOH. 

Strontian, town in Scotland) Isolated by Davey by electrolysis in 1808 however, Adair Crawford in 1790 recognized a new mineral (strontianite) as differing from other barium minerals. 

Strontium is found chiefly as celestite and strontianite. The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Three allotropic forms of the metal exist, with transition points at 235 and 540oC. 

It is found only in combination with other elements, chiefly with sulfate and carbonate and is prepared by electrolysis of the chloride. 

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