Barium amalgams

The amounts of sodium and mercury are chosen so as to yield 2 kg. of a 3 per cent amalgam. They may be changed to yield other amounts of amalgam (not exceeding 4 kg.), or amalgams of a different percentage composition. 

It is by far the simpler method, gives a purer product, and is to be preferred to the displacement method. The directions given under procedure A are based essentially upon the results obtained by G. MePhail Smith and A. C. Bennett and involve the electrolysis of a saturated solution of barium chloride using a mercury cathode. The displacement method is given as an optional procedure. 

One hundred milliliters of a saturated solution of barium chloride is placed in a 250-ml. beaker, and 250 g. of pure mercury is added. Electrical contact with the latter, serving as the cathode, is made by means of a platinum wire fused through the end of a glass tube. A platinum foil (5 to 10 sq. cm.) bent at right angles, but parallel to the mercury cathode, is used as the anode. 

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By acting upon a solution of baric chloride with sodium amalgam, barium amalgam is produced. 

The first three are illustrated by specific examples in the syntheses that follow. Sodium amalgam (synthesis 4) is readily prepared by direct combination of the metal with mercury (illustrating method 1). Barium amalgam (synthesis 5) can be produced readily by the electrolysis of a saturated aqueous solution of barium chloride with a mercury cathode (illustrating method 2a). Barium amalgam is also easily obtainable by the action of sodium amalgam upon a concentrated aqueous solution of barium chloride (illustrating method 3). 

Barium amalgam, 11 by displacement method, 14 by electrolytic method, 12 Barium paraperiodate, 171 Benzalazine, 92... 

Strontium and barium amalgams are prepared by electrolysis of solutions of the corresponding chlorides on mercury cathodes. The directions for the compound are each applicable to the other. 

BARIUM AMALGAM (APPLICABLE ALSO TO STRONTIUM AMALGAM)... 

Barium was first identified in the mineral barite by the Swedish chemist Scheele in 1774. The pure element was first prepared in 1808 by British chemist Sir Humphry Davy, who produced barium amalgam by electrolyzing an aqueous solution of barium chloride using a liquid-mercury cathode. After distilling mercury from the barium amalgam formed, he obtained pure barium metal. 

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