Hydrazine sulfate

  • Hydrazine sulfate
  • Hydrazoniumsulfat

Colorless, crystalline, odorless solid

1.37 g · cm -3 ( 20 ° C)

254 ° C ( with decomposition)

Poorly in water (30 g · l-1 at 20 ° C)


  • 201 mg · kg -1/8 days ( TDLo, man, oral)
  • 434 mg · kg -1 ( LD50, mouse, oral)
  • 601 mg · kg -1 ( LD50, rat, oral)

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Hydrazinium sulfate is a salt of hydrazine and sulfuric acid. The colorless substance is an intermediate product in the preparation of pure hydrazine.

Production and representation

By the reaction of sulfuric acid with hydrazine

Or hydrazine hydrate

On a laboratory scale, the N2H6SO4 can be represented by the reaction of a urea solution with basifizierter NaOCl solution and subsequent acidification with sulfuric acid:

In another laboratory synthesis of a Hydraziniumazidlösung is reacted with sulfuric acid to form the sparingly soluble hydrazinium fails.


Hydrazine forms colorless crystals. It is much less soluble than in hot, which is utilized in the laboratory synthesis of hydrazine ( N2H4 ) in cold water by allowing the hydrazine crystallize for cleaning as sulfate and then recrystallized once more for the further course again the hydrazine (hydrate ) release.

The salt crystallizes in orthorhombic crystal lattice with space group P212121. It was in the solid phase a N2H62 SO42 - proven structure, because of a much higher lattice energy against a N2H5 HSO 4 - is preferred structure. In aqueous solution, because of the very low second KB2 value of hydrazine, an immediate equilibration to N2H5 - and HSO 4 - ions.

At 254 ° C melts the N2H6SO4 wherein it already starts at a temperature of about 250 ° C to decompose. When annealing the pure product no residue, which can be used as a purity test of hydrazine sulfate remains.


The sulfate is used as a reducing agent ( mineral analysis), and it serves as Trennungsreagenz in the manufacture of polonium. In addition, to use it for the synthesis of azides and hydrazine hydrate.


Hydrazinium represents a strong reducing agent, and therefore should not be brought into contact with oxidizing agents. When people showed up at a dose of 201 mg / kg body weight over a period of eight days, drowsiness, nausea, and paresthesia. There is the risk of sensitization by skin contact. In addition, hydrazinium sulphate is probably carcinogenic to humans.