Preparation of Sodium Bisulphide

Preparation of Sodium Bisulphide. Assemble an apparatus as shown in Fig. 66. Fill drying columns 4 with. phosphorus(V) oxide placed on glass wool. Weigh 2-2.5 g of metallic sodium, wash it with benzene and diethyl ether, thoroughly remove the oxide film from its surface, cut the sodium up into small pieces, and put them into test tube 2. Pour 75 ml of absolute ethanol into 150-200-ml round-bottomed flask 1. Fill the apparatus with dry argon (nitrogen) via tube 3. 

By turning test tube 2 about the ground-glass joint during 10-15 min, introduce the taken amount of sodium into reaction flask 1. 

After complete dissolution of the metal (the solution may be slightly turbid), pass a strong stream of dry hydrogen sulphide through tube 3 during one hour. 

If a substantial amount of sulphur precipitates during the reaction, filter the solution in an inert argon or nitrogen atmosphere through a glass filter No. 2 (see Fig. 645). The receiver for the filtrate must be clean and dry. Keep the inert atmosphere and add 250-300 ml of absolute diethyl ether to the filtrate, introducing it in 20-25-ml portions every 10 minutes. 

Separate the precipitated sodium bisulphide crystals by means of a glass filter No. 2, wash it with absolute diethyl ether, and transfer it for drying into a test tube with a ground-glass joint. Connect the test tube to a vacuum system and keep it under a vacuum (10- mmHg) at 20 G during 30 minutes. Put the dry preparation 

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