Hydrazine is a very powerful reducing agent.  It is most reductive under basic conditions, forming water and nitrogen gas.

Also in the presence of oxygen, when catalysed by transition metal ions, hydrogen peroxide and nitrogen are produced.   The hydrogen peroxide in the presence of the metal ions, however may reduce into water, giving similar products to above

Another use for hydrazine and some related alkylated compounds, is that they are used as rocket fuels. Anhydrous hydrazine as well as mono methyl hydrazine and unsymetrical dimethyl hydrazine can be used as mono- and bi-propellants.  Mono-propellant systems, are systems where decomposition is triggered when the hydrazine is placed in contact with a catalyst, giving enough thrust for very precise movements including small changes in altitude or roll, which can be fired many times over until the correct position in space is achieved.    Bi-propellant systems use liquid hydrazine and an oxidant which, on contact degrade giving enough power to launch spacecraft such as Titans, Delta and Ariane 4.  Bi-propellant systems can generate up to 1,000,000 pounds of thrust without the need for external ignition systems.  The oxidants used have varied over the years.  In the late 1950's chlorine trifluoride was used although it was found to be extremely reactive and toxic and the handling problems outweighed its performance benefits.  Another oxidant around at the same time was perchloryl fluoride, which was slightly cheaper than the chlorine trifluoride, but still had many of the safety risks. The picture shows Ariane 1. Ariane 1 was first launched on the 24th December 1979, and was last launched on the 22nd of June 1986. Ariane 1 had a total mass of 207,200 kg and was 50.0 metres long.

The launch price in 1985 dollars was $32 million. The propellants used in stage numbers one and two were a mixture of unsymetrical di-methyl hydrazine and dinitrogen tetroxide as the oxidant.