Amalgams of Lanthanum, Neodymium, and Cerium

This method may be used for the preparation of the amalgams in any desired quantity. 

Apparatus. The electrolytic cell consists of a 250-ml. widemouthed Erlenmeyer or Florence flask (pyrex) into 

Manipulation. A concentrated solution of the anhydrous rare earth chloride J in ethyl alcohol (20 to 30 g. chloroform per 100 ml. absolute ethanol) is electrolyzed using a 110-volt direct current with the cell in series with a variable resistance. The current density should not exceed 0.05 to Fig. i.—Ceil for 0.1 amp. per square centimeter in order to eaXamargam8.rare Prevent dispersion of the mercury. The solution is electrolyzed for 15 to 40 hours. Under these conditions, a liquid to pasty amalgam is obtained containing 1 to 3 per cent of rare earth metal by weight. Results of typical runs are given in the accompanying table. 

Upon conclusion of the electrolysis, the electrolyte is decanted as completely as possible from the amalgam. The 

Amount and salt used Vol. of CJIsOH, ml. Cone, of amalgam, % by weight Time of electrolysis, hr. Average current density, amp./sq. cm. 

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The preparation of amalgams of lanthanum, neodymium, and cerium by electrolysis of the anhydrous chlorides in alcoholic solution has already been described. The electrolysis of a rare earth chloride in water solution proves unsatisfactory because of the production of a precipitate of hydrous oxide at the cathode and the liberation of chlorine at the anode. 

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