Hydrazine hydrate properties

The many advantageous properties of hydrazine ensure continued commercial utility. Hydrazine is available in anhydrous form as well as aqueous solutions, typically 35, 51.2, 54.4, and 64 wt % N2H4 (54.7, 80, 85, and 100% hydrazine hydrate). 

The freezing point diagram for the hydrazine—water system (Eig. 1) shows two low melting eutectics and a compound at 64 wt % hydrazine having a melting point of —51.6°C. The latter corresponds to hydrazine hydrate [7803-57-8] which has a 1 1 molar ratio of hydrazine to water. The anomalous behavior of certain physical properties such as viscosity and density at the hydrate composition indicates that the hydrate exists both in the Hquid as well as in the soHd phase. In the vapor phase, hydrazine hydrate partially dissociates. 

Table 1 summarizes some of the physical properties of anhydrous hydrazine, hydrazine hydrate, monomethyUiydrazine, and unsymmetrical dimethyUiydrazine (6—8). A comprehensive review of the physical and thermodynamic properties of the hydrazines is available (9). 

The catalytic activity of PCSs results from their semiconductor properties. The first studies in this field date from 1959—1961. Thus, we have demonstrated catalytic activity of products of the thermal transformation of PAN in the decomposition reactions of hydrogen peroxide, hydrazine hydrate, and formic acid270, 271. There is an indication of catalytic activity of poly(aminoquinone) in the reactions of the hydrogen peroxide decomposition272. ... 

When sebacic dihydrazide reacts with hydrazine hydrate the product formed is polyoctamethylene-4-amino-1, 2, 4-triazole, that resembles poly (hexamethylene adipamide) in properties. 

Hydrazine hydrate is toxic by all routes of exposure. Toxic properties are similar to hydrazine (See Hydrazine.)... 

Thermal, Combustion and Explosion Properties. Ign temperatures of 85% hydrazine hydrate in pyrex and air was found to be 292°C. Oxygen lowered the ignition point to 218°C. On platinum foil an air atmosphere gave an ignition... 

Properties. 1. Pour 5 ml of water into each of two test tubes, and introduce 2-3 drops of hydrazine, hydrazine hydrate, or several crystals of hydrazine sulphate into them. Add several drops of iodine water into one tube. What is observed Write the equation of the reaction. Add solutions of copper(II) chloride and an alkali into the other tube. Carefully heat its contents. What happens Write the equation of the reaction. What properties do hydrazine compounds have ... 

What is the structure of hydrazine, hydrazine hydrate, hydrazine sulphate, and hydroxylamine Do these compounds exhibit oxidizing properties ... 

In relatively recent times Scott, Jones and Lewis [48] made detailed studies of the explosive properties of hydrazine and 85% hydrazine hydrate. In the drop test, neither hydrazine nor hydrazine hydrate were exploded by a very strong blow (5 kg from 1 m height). Hydrazine and its hydrate are also insensitive to friction. The authors attempts to determine the rate of detonation of hydrazine in pipes also failed since hydrazine is initiated by a detonator with difficulty. The reaction in the ballistic pendulum, of charge of anhydrous hydrazine initiated by No. 8 detonator, was 135% of that produced by TNT. Under these conditions hydrazine hydrate does not detonate at all. 

The cis-[Pt(PR3 )2Cl2] compounds, where R = alkyl, were converted smoothly to trans-[Pt(PR3 )2HCl] by treating them with hydrazine hydrate in a mixture of ethanol and chloroform. Chloroform must be added since the complexes are insoluble in pure ethanol. The hydride complexes are cream-colored, low-melting, crystalline solids that closely resemble the physical properties of the parent dichloro complexes. 

In liquid hydrazine, hydrogen bonding occurs between the hydrazine molecules similar to the hydrogen bonding in liquid water. In solid hydrazine, the hydrogen bonds have NH-N distances between 319 and 367 pm. In hydrazine hydrate, each hydrazine molecule is linked via six hydrogen bonds to surrounding water molecules so that the hydrazine molecules are separated from each other by water molecules. Some physical properties of hydrazine and hydrazine hydrate are shown in Table 16. 

Table 16 Physical properties of hydrazine and hydrazine hydrate...

To improve the aging property of E-SBR, Parker and Roberts used the diimide reduction method to prepare hydrogenated E-SBR. In the system containing hydrazine hydrate, oxidant, and a metal-ion catalyst, hydrogenated E-SBR with 97%o of hydrogenation could be obtained. The hydrogenated E-SBR not only exhibited excellent ozone, oxidation, and UV resistance as expected, but also showed better mechanical properties in some circumstances than unhydrogenated E-SBR. 

Hydrazine nitrate shows high solubility in the hydrazine hydrates aqueous solution. Dissolving hydrazine nitrate into hydrous hydrazine hydrate can also produce liquid explosives with good performance. For example, the liquid explosive from a mixture of 77.8 % Hydrazine nitrate, 20.1 % hydrazine hydrate, and 2.1% water can achieve a high detonation velocity of 8,370 m/s at the density of 1.42 g/cm. Moreover, it is not sensitive to mechanical shock and shows good reliability and fuU detonation [56]. The freezing point for this liquid explosive, however, is high [57]. Table 7.41 compares the component and properties for some hydrazine nitrate and hydrazine hydrate liquid explosives. 

Table 7.41 Component materials and properties for hydrazine nitrate and hydrazine hydrate liquid explosives [1]...

Table 7.48 Physical and chemical properties of hydrazine hydrate diluted by equimolar 80 % hydrogen peroxide and methanol...

In 2003, it was suggested to use this substance in a fuel cell with proton-conducting (i.e., an acid) membrane. Hydrazine was used as a 10% aqueous solution of hydrazine hydrate (N2H4-H20). In the aqueous solution, hydrazine, on account of its strong alkaline properties, dissociates into the ions N2H5+ and OH . The anodic oxidation of hydrazine can be written in terms of the equation ... 

According to Chinese authors [17] researchers outside China use 30 % nickel nitrate and a 40 % solution of hydrazine hydrate. Using solutions of such a high concentration leads to the formation of a hght pink powder with unsuitable properties. To obtain good product, the Chinese use lower concentrations in both nickel nitrate (5-10 %) and hydrazine hydrate (10-15 %). The reaction temperature is 50-70 °C and within 30-40 min yields about 80 % of product in the form of spherical crystals of NHN with density 1.0 g cm. ... 

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