The Chemistry of Powder and Explosives - Sciencemadness Dot Org

LEAD AZIDE 427
the interaction of hydrazine with esters just as the amides are
formed by the corresponding interaction of ammonia.
R_COOC2Hi + NH2—NHj > C2H6OH + R—CO—NH—NH2
Acyl hydrazide
R—CO—NH—NH2 + HONO > 2H2O + R—CO—N3
Acyl azide
R—CO-N3 + H2O — > R—COOH + HN3
R—CO—N3 + NH3
> R—CO—NH2 + HN3
Hydrazoic acid
By acidifying the hydrolysis mixture with sulfuric acid and by
fractionating the product, Curtius procured anhydrous hydrazoic
as a colorless liquid which boils at 37°. Hydrazoic acid is intensely
poisonous and bad smelling. It is easily exploded by
flame, by a brisant explosive, or by contact with metallic mercury.
The anhydrous substance is extremely dangerous to handle,
but dilute solutions have been distilled without accident.
Angeli 35 obtained a white precipitate of insoluble silver azide
by mixing saturated solutions of silver nitrite and hydrazine sulfate
and allowing to stand in the cold for a short time. Dennstedt
and Gohlich 36 later procured free hydrazoic acid by the interaction
of hydrazine sulfate and potassium nitrite in aqueous
solution.
NH2—NH2 • H2SO4 + KONO > KHSO4 + 2H2O + HN3
Hydrazine sulfate
The yield from this reaction is greatest if the medium is alkaline,
for nitrous acid attacks hydrazoic acid oxidizing it with the liberation
of nitrogen. If hydrazine sulfate " is used in the mixture,
the resulting hydrazoic acid is not available for the preparation
of lead azide until it has been distilled out of the solution. (Lead
ions added to the solution would cause the precipitation of lead
sulfate.) The reaction mixture may be acidified with sulfuric
acid, a little ammonium sulfate may be added in order that the
33 Rend. ace. Lincei, [51 2, I, 599 (1893).
^ Chem.-Ztg., 21, 876 (1897).
37 Hydrazine is produced commercially by treating ammonia in aqueous
solution with sodium hypochlorite to form chloramine, NH2—Cl, and by
coupling this with another molecule of ammonia to form hydrazine and
hydrochloric acid. Sulfuric acid is added to the liquid, sparingly soluble
hydrazine sulfate crystallizes out, and it is in the form of this salt that
hydrazine generally occurs in commerce.