Nonaqueous Solutions of Hydrazoic Acid

One of the more frequently used solvents for hydrazoic acid is ethyl ether. If a small water content (approximately 1%) can be tolerated, an aqueous solution of HN3 may be extracted with ether in a separatory funnel. Such an 

Solutions of hydrazoic acid in methanol are obtained by bubbling an air/ hydrazoic acid mixture into dry methanol for example [55], using a 250-ml flask, hydrazoic acid vapor from 10 g sodium azide and sulfuric acid is mixed with a stream of air, and the vapors are absorbed in -40°C methanol (200 ml) within 90 min. 

Chloroform solutions are made by covering a slurry of equal parts sodium azide and water with three parts chloroform the mixture is cooled to 0°C. Concentrated sulfuric acid (one equivalent for two of sodium azide) is added to this between 0 and +10°C. The solution is then decanted and dried over sodium sulfate [56]. 

Similarly, sodium azide may be placed under carbon tetrachloride to be decomposed with concentrated sulfuric acid [57] the carbon tetrachloride solution is then decanted. Alternatively, sodium azide and the tetrachloride are treated in a separatory funnel with diluted d, 1.5) phosphoric acid [58]. 

The above technique for chloroform may also be used for benzene and xylene solutions of hydrazoic acid [56], unless the following, somewhat more elaborate, method is used 70 g pulverized sodium azide is placed in a beaker containing 500 ml dry benzene. The exact amount of HCl gas, made by decomposing 58 g sodium chloride with concentrated sulfuric acid, is bubbled into the vigorously stirred azide suspension. The hquid is then stirred until chloride-free and filtered. Due to some evaporation of hydrazoic acid, the solution is 6-7% concentrated (theoretically 8%) [59]. 

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