Molecular Structure and Properties
Hydrazine forms a monohydrate that is more dense (1.032 g/cm3) than the anhydrous material.
Hydrazine can arise via coupling a pair of ammonia molecules by removal of one hydrogen per molecule. Each H2N-N subunit is pyramidal in shape. The N-N distance is 1.45 Å (145 pm), and the molecule adopts a gauche conformation. The rotational barrier is twice that of ethane. These structural properties resemble those of gaseous hydrogen peroxide, which adopts a "skewed" anticlinal conformation, and also experiences a strong rotational barrier.
Hydrazine has basic (alkali) chemical properties comparable to those of ammonia:
- N2H4 + H2O → + + OH−
with the values:
- Kb = 1.3 x 10−6
- pKa = 8.1
(for ammonia Kb = 1.78 x 10−5)
Hydrazine is difficult to diprotonate:
- + + H2O → 2+ + OH− Kb = 8.4 x 10−16
The heat of combustion of hydrazine in oxygen (air) is 194.1 x 105 J/kg (9345 BTU/lb).
Read more about this topic: Hydrazine
Famous quotes containing the words structure and/or properties:
“Just as a new scientific discovery manifests something that was already latent in the order of nature, and at the same time is logically related to the total structure of the existing science, so the new poem manifests something that was already latent in the order of words.”
—Northrop Frye (b. 1912)
“A drop of water has the properties of the sea, but cannot exhibit a storm. There is beauty of a concert, as well as of a flute; strength of a host, as well as of a hero.”
—Ralph Waldo Emerson (1803–1882)