Hydrazine sulfate
Hydrazine sulfate is a useful salt that finds its use mainly in organic sythesis. It was at one point thought to be effective at treating cancer, however this was disproven.
Contents
Properties
Chemical
Hydrazine sulfate has the molecular formula N2H6SO4, however this is better represented as N2H5HSO4. It finds uses in organic chemistry, mainly by forming hydrazides.
Physical
Hydrazine sulfate is a white crystalline solid melting at 254°C.
Availability
Hydrazine sulfate is not very readily available for purchase to the amateur, but it is easily and cheaply made at home.
Preparation
There are many ways in which an amateur can produce hydrazine sulfate. Two important ones which give decent, around 50%, yields are shown below.
Hypochlorite-Ketazine Process
Concentrated(20 - 30%) ammonia is mixed with methyl ethyl ketone and a few hundred mg of gelatin and cooled down to 0°C. Sodium hypochlorite is then added dropwise until the stoichiometric amount has been added. A hydrophobic azine (methyl ethyl ketazine) which is less dense than water, will then separate. This azine is then mixed with a stoichiometric amount of ~17% sulfuric acid, and heated to the boiling point of MEK to ensure full hydrolysis of the azine. Finally, the solution is chilled to 0°C to precipitate the hydrazine sulfate. The solution is then vacuum filtered.[1]
Hoffman Rearrangement of Urea
A solution of 10% sodium hypochlorite is added to solid sodium hydroxide and the mixture is kept cold during the addition. Meanwhile, a solution of urea with a few hundred mg of gelatin is prepared. The two solutions are mixed and allowed to fully react, a voluminous foam will appear. After they have reacted, MEK is added to the solution and the azine is processed as previoulsy described.[2]
Projects
When mixed with a solution of silver nitrate, a silver mirror will be formed on the surface of the container. Hydrazine sulfate also finds a variety of uses in organic syntheses such as the preparation of 2,4 dinitrophenylhydrazine, and the preparation of luminol.
Safety
Hydrazine sulfate is much safer than its free base, hydrazine. However, it is still moderately toxic and a suspected carcinogen. It may ignite on contact with certain strong oxidizers.
