Potassium nitrate, structure

Grayish-white metal hody-centered cubic crystalline structure density 19.3 g/cm3 melts at 3,422°C vaporizes at 5,555°C vapor pressure 1 torr at 3,990°C electrical resistivity 5.5 microhm-cm at 20°C modulus of elasticity about 50 to 57 x lO psi (single crystal) Poisson s ratio 0.17 magnetic sus-ceptibilty +59 x 10-6 thermal neutron absorption cross section 19.2 + 1.0 barns (2,200m/sec) velocity of sound, about 13,000 ft/sec insoluble in water practically insoluble in most acids and alkabes dissolves slowly in hot concentrated nitric acid dissolves in saturated aqueous solution of sodium chlorate and basic solution of potassium ferricyanide also solubibzed by fusion with sodium hydroxide or sodium carbonate in the presence of potassium nitrate followed by treatment with water... 

Figure 3. Structures of the polyhorates with the log formation constants for 0.05M boric acid at 25°C in 0.15M potassium nitrate...

Some molecules have structures that are not expressed correctly by a single Lewis structure. For example, consider the nitrate ion, N03-, which, as potassium nitrate, is used in fireworks and fertilizers. The three Lewis structures shown in (11) differ only in the position of the double bond. 

J. W. Briihl s observations on the refractive indices agreed with the formula H0.0.N=0 but R. Lowenherz s values for ethyl, propyl, isobutyl, and amyl nitrates agree better with the quinquevalent nitrogen atom. H. E. Armstrong and F. P. Worley made some observations on the constitution of nitric acid—vide sulphuric acid. H. Burgarth, H. Remy, and H. Henstock discussed the electronic structure and from observations on the absorption spectra of sodium and potassium nitrates in different solvents, G. Scheibe inferred that the nitrate ion is dipolar, and that the electronic structure is such that the first of the following forms exists in equilibrium with small proportion of the second ... 

Fluorine Miscellaneous materials, 4304 Magnesium perchlorate Cellulose, etc., 4078 /V-Meth yI morpholine oxide, 1991 Nitric acid Cellulose, 4430 Perchloric acid Cellulose and derivatives, 3992 Perchloric acid Hydrofluoric acid, Structural materials, 3992 Potassium chlorate Cellulose, 4011 Potassium nitrate Cellulose, 4645 Sodium chlorate Paper, etc., or Wood, 4033 Sodium nitrate Fibrous material, 4716 Sodium nitrite Wood, 4715 Sodium peroxide Fibrous materials, 4797 Zinc permanganate Cellulose, 4705 BLEACHING POWDER Wood perchlorates Organic matter See SUGARS... 

Organic substances such as methane, naphthalene, and sucrose, and inorganic substances such as iodine, sulfur trioxide, carbon dioxide, and ice are molecular solids. Salts such as sodium chloride, potassium nitrate, and magnesium sulfate have ionic bonding structures. All metal elements, such as copper, silver, and iron, have metallic bonds. Examples of covalent network solids are diamond, graphite, and silicon dioxide. 

In the days when anhydrous nitric acid was not easily available, nitric acid salts (NaN03, KN03) mixed with sulphuric acid were widely used for nitration. Such mixtures acted similarly to the mixture of nitric and sulphuric acids. Later, as synthetic nitric acid became one of the most readily available chemical products, and the production of nitric acid salts from nitric acid had started, nitrating mixtures with sodium or potassium nitrates were abandoned. This is the principal explanation for the scarcity of investigations on the structure and action of such mixtures. It is believed that in such mixtures the nitronium ions are present, according to the equation ... 

In some cases, if the complex ion is not too far from spherical, the compound may assume a structure similar to the simple ones already described, hut with slight distortion. In calcium carbide, for example, the layout of positive and negative ions is the same as in sodium chloride, but the nonspherical Cl ions are lined up with their axes parallel, distending one dimension of the square units to form rectangles. In potassium nitrate, again similar to the sodium chloride structure, the unit cell has been even further distorted from a perfect cube, all faces becoming rhombuses rather than squares. 

Freis and Reitz, using potassium nitrate in sulfuric acid on heating, have obtained two mononitrated products and assigned to them the structures of 4- and 7-nitro isomers [212], Later, this structure has been proved by a secondary synthesis [213], and the other isomer turned out to be 5-nitro-l,2,3-benzothiadiazole [214, 215], On a more careful study all three isomers were found among the reaction products, as shown in Scheme 2.18 [216],... 

Additions of crystalline oxidizers such as ammonium nitrate or potassium nitrate to nitrate esters or energetic polymers form composite explosives whose physical structures are heterogeneous. In contrast to homogeneous explosives, the energy density of composite explosives is higher than that of homogeneous explosives. 

Paramagnetic resonance has been observed [39,40] in UV- and X-irradiated KN3 crystals containing nitrite and nitrate ion impurities. The resonances were attributed to trapped NO and NO2 radicals. The axial symmetry and potassium hyperflne structure of the resonances attributed to NO2 were cited as evidence that this defect occupies a potassium ion vacancy. Fuller and Tarr [40] concluded that NO2 is a photolysis product of the nitrite ion, but not of the nitrate ion. 

Structure of the Electrolyzers. The following discussion is based on sodium sulfate, which is the by-product salt of greatest concern [228], [229]. However, many of the conclusions also apply to the electrolysis of other salts such as potassium sulfate and sodium and potassium nitrate. 

Ammonium nitrate-containing pyrotechnic gas-generating formulations may suffer from phase changes in a crystalline structure associated with volumetric expansion during temperature cycling. Potassium nitrate and cupric oxide have a synergistic effect in stabilizing ammonium ni-... 

TTie specification M1L-P-223B (1962 with Amendment 1—1963) is mandatory for all Department of Defense uses. Its formula is given under No. 146. Black powder is not strictly a mechanical mixture of potassium nitrate, sulfur, and charcoal. During the ball-milling phase of mixing the charcoal and sulfur, the latter is forced into the porous structure of the carbon. This makes the individual grain very dense. Hard compressed larger pellets or columns are relatively nonporous, so that they burn in orderly fashion. 

A disadvantage of ammonium nitrate is its hygroscopicity and a crystal-structure change that increases its volume by 3.8 % at the unfortunate transition temperature of 32 C, which is also the popular summer temperature of 90 F over most of the United States. This transition point can be shifted, i.e. depressed by about 20 , but not abolished, by admixture of 8% of potassium nitrate. 

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