Potassium nitrate, nitration with

The red [SSNO] anion (9.2) (2max 448 nm) is produced by the reaction of an ionic nitrite with elemental sulfur or a polysulfide in acetone, DME or DMSO. ° The formation of 9.2 probably proceeds via an intermediate such as the [S2NO2] anion. This process is thought to occur in the gunpowder reaction, which also entails the reaction of potassium nitrite (produced by reduction of potassium nitrate with charcoal) and sulfur. 

Most blackpowders contain 75% of potassium nitrate, 15% of charcoal and 10% of sulphur. For safety fuse, however, blackpowders are made with reduced amounts of potassium nitrate. Also manufactured are sulphurless powders, containing approximately 70% of potassium nitrate with 30% of charcoal. These sulphurless powders are used for ignition purposes where sulphur could cause corrosion of metallic components. 

A 14 kg batch of the mixture, mainly of boron and potassium nitrate, with a minority of the synthetic resin adhesive and solvent, exploded 5 min after blending had started. Several possibilities of a frictional initiation source were considered. 

Mixtures of potassium nitrate with antimony trisulfide [1], barium sulfide, calcium sulfide, germanium monosulfide or titanium disulfide all explode on heating [2]. The mixture with arsenic disulfide is detonable, and addition of sulfur gives a pyrotechnic composition [2], Mixtures with molybdenum disulfide are also detonable [3], Interaction with sulfides in molten mixtures is violent [4],... 

Mixtures of potassium nitrate with sodium phosphinate and sodium thiosulfate are explosive, the former being rather powerful. 

From the viewpoint of inorganic chemistry, the reaction of potassium nitrate with sulfur and charcoal can be described as an oxidation-reduction reaction in which electron transfer between reacting species involves a loss or gain of electrons resulting in an oxidation or reduction process respectively. 

Barium nitrate is superior to either sodium or potassium nitrate with regard to physical stability, while the heat concentration is also higher because barium oxide has better refractory properties than does either potassium or sodium oxide. 

The data in Table 7. 7 show that potassium nitrate, with its highly endothermic heat of decomposition, produces significantly lower flame temperatures with shellac than the other three oxidizers. The yellow light intensity will be substantially less for the nitrate compositions. 

For a long time attempts have been made to explain why three non-explosive substances, viz. potassium nitrate, charcoal and sulphur, when combined together should form an explosive mixture. It was particularly incomprehensible that binary mixtures of potassium nitrate with charcoal or with sulphur should be non-explosive or only poorly so. The problem was the more difficult to elucidate since it involves a reaction in the solid phase. 

Sulphur facilitates an increase in the quantity of gases evolved on explosion. In the absence of sulphur potassium nitrate with carbon gives only K2C03, but in the presence of sulphur C02 is evolved and potassium forms K2S04 and K2S. 

The quantitative determination is carried out colorimetrically in the same way with a weighed quantity of the sample. The coloration of the liquid is compared (as in estimating potassium nitrate) with a series of tubes in which solutions containing definite proportions of boric add (o-i, 02, 0-3, etc., %) are treated with the same amounts of add, alcohol and curcumin solution in each case. 

Olah et al.480 have found that nitration of aromatics with potassium nitrate or nitric acid catalyzed by boron trifluoride-monohydrate BF3-H20 proceeds with good to excellent yield and is capable of nitrating even some deactivated aromatics [Eq. (5.178)]. Later, it was shown that potassium nitrate with the complex boron trifhioride-trifluoroethanol BF3-2CF3CH2OH is equally effective481 [Eq. (5.178)]. 

Mixtures of potassium nitrate with antimony trisulfide [1], barium sulfide, calcium sulfide, germanium monosulfide or titanium disulfide all explode on heating [2]. The... 

PP3, the double salt and potassium carbonate, with potassium nitrate SP, with potassium nitrate and carbonate, with the double salt i Pj- 2j of sodium carbonate and potassium nitrate, with sodium nitrate and P2P3, with the double... 

The role played by coordination complexes as templates and catalysts in these reactions is somewhat more difficult to discern, although several important results have been reported. Some early work by Bahadur showed that amino acids were formed in the reaction of potassium nitrate with paraformaldehyde in the presence of light. Many amino acids were produced, but the highest yields were found when the reaction was carried out in the presence of iron(lll) chloride as a catalyst. Later work extended analogous findings to colloidal molybdenum oxide as the catalyst. Molecular nitrogen was fixed in this case, a reaction in a sense comparable to the... 

Tlie rates of burning of mixtures of potassium nitrate with sulphur are higher than those of potassium nitrate with carbon. 

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