Gunpowder, potassium

More exotic effects call for more exotic materials, and considerable effort has gone into formulating compositions that are both spectacular in effect and safe to produce and handle. Thus a 30 mm fountain might contain mealed (or hue) gunpowder, potassium nitrate, sulfur, charcoal, antimony trisulhde, barium nitrate, hue aluminium and flitter aluminium with a dextrin binder. This composition is certainly a good deal more complicated than that used for sparklers but is relatively safe to produce and gives a good burst of white sparks. 

Gunpowder Potassium chlorate Nitrated cellulose Gun cotton Cellulose trinitrate Smokeless powder... 

Combination reactions require that two or more components react together exothermically to produce hot gases. Some examples are ammonium nitrate and fuel oil (ANFO), gunpowder (potassium nitrate, carbon, and sulfur), and fireworks. In these explosions, the reactants that make up the explosive must be carefully mixed to assure that the reaction will continue. 

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. 

Potassium nitrate is best known as the oxidizing agent in old-fashioned black powder gunpowder, which is 75 percent potassium nitrate by weight. The other ingredients are 15 percent charcoal and 10 percent sulfur. 

A demonstration by Berthollet in 1788 of replacement of potassium nitrate in gunpowder by the chlorate led to a violent explosion during the crushing operation which caused two fatalities. Later incidents involving factories for chlorate-containing explosives led to widespread destruction. 

In the early 1700s, Henri-Louis Duhamel du Monceau (1700—1782) was the first to realize that many minerals exhibited similar alkaline (basic) characteristics. He studied samples of salts both derived artificially and found in nature, including saltpeter (potassium nitrate used in gunpowder), table salt, Glauber s salt, sea salt, and borax. 

Similar to the history of many other elements, iodine s discovery was serendipitous in the sense that no one was looking for it specifically. In 1811 Bernard Courtois (1777—1838), a French chemist, attempted to remove sodium and potassium compounds from the ash of burned seaweed in order to make gunpowder. After removing these chemicals from the ash, he added sulfuric acid (H SO j) to the remaining ash. However, he mistakenly added too much acid, which produced a violet-colored vapor cloud that erupted from the mixture. This violet vapor condensed on all the metallic objects in the room, leaving a layer of sohd black iodine crystals. Sir Humphry Davy (1778—1829) confirmed this discovery of a new element and named it iodine after the Greek word iodes, which means violet, but it was Courtois who was given credit for the discovery of iodine. 

At a temperature of 338 °C, the vibrational and translational motion overcomes the electrostatic forces holding the lattice together and the KNO3 melts. The relatively low melting points of substances such as potassium nitrate are normally directly related to ease of ignition a very important feature of gunpowder type products. 

Hence, the gunpowder reaction product, potassium carbonate, K2CO3, can be assigned the oxidation numbers K2( + 2) C( + 4) 0 (-6) on application of the above rules. 

The thermodynamic arrow of entropy points towards a natural tendency to disorder which tells us that the universe will expand rather than contract, that the bath water will run out of the bath, cooling as it does so, while gunpowder, when ignited, will disappear as smoke and flame. The latter can never reform as the intimate mixture of potassium nitrate, sulfur and charcoal from which it started - there being no going back or reversal during such processes. 

In manufacture, sulfurless gunpowders are available with a potassium nitrate content of 7(U80% and a charcoal level of 2(U30%. 

In North America the problem of moisture absorption has been addressed by developing a moisture resistant gunpowder substitute based on potassium nitrate but augmented with potassium perchlorate. The latter is said to absorb less moisture than the nitrate at a given humidity. In addition, the gunpowder substitute contains a hydrophobic binder, called ethyl cellulose, (2.22) (celluloses have a history of use in pyrotechnics) together with an organic fuel, known as phenolphthalein, (2.23) which is said to enhance the bum rate. 

Some fountain compositions tend to be oxidant-rich due to the presence of excess potassium nitrate or sometimes various oxalates. The reason for this is to reduce the burning rate and/or to enhance the visual effects. Certainly if gunpowder is considered to be a mixture of fuels (charcoal and sulfur) and oxidant (potassium nitrate) then the maximum rate of burning should coincide with a slightly under-oxidised system. The burning rate is therefore reduced by adding excess nitrate to the system. 

In operation, the mealed gunpowder provides the gas and heat necessary for the combustion of the other fuels and oxidisers that are present. The potassium sulfide that is formed produces orange-red sparks, whereas the steel particles contribute with gold ones. Pine needle-shaped sparks may also be seen when a spark suddenly breaks up into smaller particles. This phenomenon is said to be the result of residual carbon particles exploding in a glowing, active material. 

BLACK POWDER (synonymous with Gunpowder) An intimately milled mixture of potassium nitrate, sulfur and charcoal that has propellant or explosive properties. 

SULEURLESS GUNPOWDER A grade of gunpowder in which the sulfur is omitted and the proportion of charcoal is increased to maintain the correct fuel balance against the potassium nitrate. Mainly used in hreworks where there may be compatibility issues due to sulfur (e.g. in the proximity of chlorates). 

Once the reactive tendencies of potassium nitrate were unleashed it was simply a matter of time before the third vital ingredient, charcoal, was added to complete the famous gunpowder recipe of charcoal, sulfur and potassium nitrate. Needless to say, much time and effort were expended before the alchemists produced a successful product. 

In 1775 Lavoisier was appointed to a government post. He was made one of the four commissioners of the Gunpowder and Saltpeter Administration, which was responsible for the production of gunpowder and acquisition of one of its essential ingredients, saltpeter (potassium nitrate). At the time, the supplies of saltpeter in France were inadequate and the French were forced to buy it from the Dutch, who imported it from India. 

Gunpowder is simply a mixture of charcoal, sulfur, and potassium nitrate. Carbon and S react with 0 in the nitrate, and the N in the nitrate also releases heat in converting to N2 (the K combines with something to form the smoke). The reactions are approximately... 

Nitric acid is one of the most important industrial chemicals in the world. Its largest use is in the fertdizer industry for producing various nitrate fertd-izers. Such fertilizers include ammonium-, sodium-, potassium-, and calcium nitrates. Other major apphcations of nitric acid are in making nitrates and nitrooganics for use in explosives, gunpowder, and fireworks. Ammonium nitrate, nitroglycerine, nitrocellulose, and trinitrotoluenes are examples of such explosives, while barium and strontium nitrates are used in fireworks. 

Potassium nitrate is used in explosives, blasting powders, gunpowder, matches, and fireworks. Other applications of this salt include pickling meats tempering steel impregnating candle wicks freezing mixtures preparing other potassium salts and as a diuretic. 

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