Ammonium nitrate, properties, chemical physical

Physical and Chemical Properties. Ammonium nitrate is a white, crystalline salt, df = 1.725, that is highly soluble in water, as shown in Table 3 (7). Although it is very hygroscopic, it does not form hydrates. This hygroscopic nature compHcates its usage in explosives, and until about 1940, was a serious impediment to its extensive use in fertilizers. The soHd salt picks up water from air when the vapor pressure of water exceeds the vapor pressure of a saturated aqueous ammonium nitrate solution (see Table 4). 

Some of the physical and chemical properties of ammonium nitrate are given in Table 10.2103. 

Ammonium nitrate Physical properties Chemical and explosive properties Ihermal decomposition Explosive decomposition and stability Commercial product... 

The chemical shift of nuclei was one of the first surprises of the physicists starting NMR, which spoiled the picture for them, and made NMR spectroscopy to be a tool for chemists and biochemists. Chemical shift is the property of nuclei to resonate in an external magnetic field at a frequency that depends on the chemical environment. Thus, physically identical nuclei such as in different chemical environments resonate at different frequencies. This phenomenon was first observed in 1950 on the two resonances of ammonium nitrate [20]. The authors did not publish the spectrum obtained. Therefore, a 30-MHz spectrum of EtOH recorded in 1951 is presented here [21] (Fig. 3). For comparison with the 30-MHz spectrum, a H- spectrum of hen egg white lysozyme recorded at 900 MHz in the year 2000 is shown in Fig. 4. With present resolution of spectrometers of 10 , chemical shifts can in principle be resolved at the ppb level. 

Atmospheric aerosols have a direct impact on earth s radiation balance, fog formation and cloud physics, and visibility degradation as well as human health effect[l]. Both natural and anthropogenic sources contribute to the formation of ambient aerosol, which are composed mostly of sulfates, nitrates and ammoniums in either pure or mixed forms[2]. These inorganic salt aerosols are hygroscopic by nature and exhibit the properties of deliquescence and efflorescence in humid air. That is, relative humidity(RH) history and chemical composition determine whether atmospheric aerosols are liquid or solid. Aerosol physical state affects climate and environmental phenomena such as radiative transfer, visibility, and heterogeneous chemistry. Here we present a mathematical model that considers the relative humidity history and chemical composition dependence of deliquescence and efflorescence for describing the dynamic and transport behavior of ambient aerosols[3]. 

Elemental composition (anhydrous salt) Pt 47.60%, H 0.49%, Cl 51.90%. The compound may be identified by its physical and chemical properties. Platinum in an aqueous solution of the compound can be analyzed by flame AA or ICP spectroscopy. Also, the compound can be measured by gravimetry following precipitation with ammonium chloride, hydrogen sulfide, or silver nitrate (see Reactions above). 

Trivalent chromium compounds, except for acetate, nitrate, and chromium(III) chloride-hexahydrate salts, are generally insoluble in water. Some hexavalent compounds, such as chromium trioxide (or chromic acid) and the ammonium and alkali metal (e.g., sodium, potassium) salts of chromic acid are readily soluble in water. The alkaline metal (e.g., calcium, strontium) salts of chromic acid are less soluble in water. The zinc and lead salts of chromic acid are practically insoluble in cold water. Chromium(VI) compounds are reduced to chromium(III) in the presence of oxidizable organic matter. However, in natural waters where there is a low concentration of reducing materials, chromium(VI) compounds are more stable (EPA 1984a). For more information on the physical and chemical properties of chromium, see Chapter 3. 

Isotopes—Two molecules in which the number of atoms and the types of atoms are identical, but their arrangement in space is different, resulting in different chemical and physical properties. Nitrogen cycle—series of chemical reactions by which elemental nitrogen in the atmosphere is converted to nitrates and ammonium compounds, those compounds are processed through the plant and animal world, and then are returned to the atmosphere as free nitrogen. 

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