Potassium nitrate fireworks

Black powder, a mixture of potassium nitrate, sulfur, and carbon, may have been invented in 10th centuiy China for fireworks. There is written record they used it in bamboo tubes to propel stone projm - es. There is evidence that Arabs invented it around 1300 A. D. using a gun rf... 

Black powder is the oldest explosive in history, dating back to the eighth century. Its chemical composition is well-known as a mixture of potassium nitrate, sulfur, and charcoal. The mixture ratio is varied according to the purpose for which it is to be used, with the ranges kno3(0-58-0.79), (0.08-0.20), and ( (0.10-0.20). Black powder composed of particles less than 0.1 mm in diameter is used for shell burst of fireworks and fuses. The grade with diameter 0.4—1.2 mm is used for the launch of spherical shells of fireworks, while that with diameter 3-7 mm is used in stone mines. Since black powder is sensitive to sparks caused by mechanical impact, friction, and static electricity, black powder containers should be made of brass or aluminum alloys rather than iron or steel. When Cl and Ca or Mg are present as impurities, CaClj or MgClj is formed and the thermal performance of KN is reduced. Contamination with NaCl also needs to be avoided for the same reason. 

In forming whistling fireworks, the aromatic compounds described above are mixed with oxidisers such as potassium nitrate or potassium perchlorate and pressed into tubes. On combustion, a loud whistling sound is produced, whose pitch is related to the length and diameter of the tube. 

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. 

The use of pyrotechnic mixtures for military purposes in rifles, rockets, and cannons developed simultaneously with the civilian applications such as fireworks. Progress in both areas followed advances in modern chemistry, as new compounds were isolated and synthesized and became available to the pyrotechnician. Berthollet s discovery of potassium chlorate in the 1780 s resulted in the ability to produce brilliant flame colors using pyrotechnic compositions, and color was added to the effects of sparks, noise, and motion previously available using potassium nitrate-based compositions. Chlorate -containing color-producing formulas were known by the 1830 s in some pyrotechnicians arsenals. 

The origin of pyrotechnics is obscure and the Chinese are usually credited with the invention of pyrotechnics (gunpowder-a pyrotechnic mixture of charcoal, potassium nitrate and sulfur). Pyrotechnics are among the oldest explosive devices known to man and have been used from very early times to display fireworks for celebrating important occasions or to express victory. Fireworks are believed to be similar to pyrotechnics with minor differences. 

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. 

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. 

Potassium nitrate, KN03, is used to make fireworks. What is the mass percent of oxygen in potassium nitrate ... 

The art of using mixtures of chemicals to produce explosives is an ancient one. Black powder—a mixture of potassium nitrate, charcoal, and sulfur—was being used in China well before 1000 a.d. and has been used through the centuries in military explosives, in construction blasting, and in fireworks. The DuPont Company, now a major chemical manufacturer, started out as a manufacturer of black powder. In fact, the founder, Eleuthere du Pont, learned the manufacturing technique from none other than Lavoisier. 

Generally firework compositions which contain potassium chlorate, perchlorate or ammonium perchlorate as oxidizer will detonate from a strong mechanical initiation, especially when the composition are in the powdered state.Potassium chlorate or other chlorate, red phosphorus, realgar, sulphur, antimony trisulfide etc. promote the inclination. On the contrary, potassium nitrate or other nitrates decrease it. Black powder is not likely to detonate. 

The compositions by R.Lancaster(P.Lancaster Fireworks, principles and practice,p.89(1972)) contain gunpowder(black powder), sulphur, potassium nitrate, charcoal etc., and the twinkling or glittering effect might be caused by the Senko-Hanabi reaction of the cinder. 

It is thought that fireworks began with the history of potassium nitrate. It has. been used for compositions which produce fire dust or sparks as well as a white smoke which has been called "Wabi (Japanese fire). It could not produce coloured flames, but before the appearance of potassium chlorate, fireworkers made various efforts to create colour with it as far as possible. 

The ammonium nitrate which is produced by above reaction is quite hygroscopic. Therefore if a composition which contains ammonium perchlorate comes in contact with another composition which contains potassium nitrate such as black powder, a wet layer of ammonium nitrate occurs between the two compositions and causes misfire. With barium nitrate this double decomposition does not occur, and a mixture of barium nitrate and ammonium perchlorate is allowed in the preparation of firework compositions. 

Sulphur ignites at 223 C in the air. This relatively low ignition temperature is often used for firework compositions for ease of ignition. Sulphur is used as a raw material for black powder in combination with potassium nitrate and charcoal and it is also used for white smoke compositions. 

The boric acid prevents the potassium nitrate and aluminium from reacting v ith each other(R.Lancaster Fireworks, p.31(1972)). No.l and No.2 produce a pretty golden fire dust. No.3 produces a somewhat reddish gold effect, and looks more elegant than Nol and No.2. When we use antimony trisulphide, sulphur and realgar, as components in one composition with various ratios between them, various colour tones of gold can be obtained. 

This is insensitive to shock or friction. The boric acid suppresses the reaction of.the aluminium with the potassium nitrate in the wet state avoiding the generation of heat(R.Lancaster Fireworks, Principles and Practice, page 31(1972)). 

Your company has been contacted by a fireworks factory. A mislabeled container of sodium chloride, NaCl, was accidentally mixed with potassium nitrate, KNO3. KNO3 is used as an oxidizer in fireworks to ensure that the fireworks burn thoroughly. The fireworks company wants your company to investigate ways they could separate the two compounds. They have provided an aqueous solution of the mixture for you to work with. 

Figure 7-4a shows a deposit of sodium chloride, or table salt—the most common sodium compound. Table salt occurs naturally in many foods. It is used to keep food from spoiling and to preserve foods for long-term storage, as shown in Figure 7-4b. These roles were especially important before the widespread use of refrigeration. Potassium chloride serves as a salt substitute for people whose intake of sodium must be limited. Potassium compounds are included in fertilizers because potassium is an important factor for plant growth and development. Potassium nitrate is used as an explosive for large-scale fireworks displays.

Potassium Nitrate, KN03, crystallises in large prisms, isomorphous with nbic aragonite, and so is sometimes known as prismatic saltpetre. It is. principally for the production of black shooting powder and for fireworks. However, since the production of the new smokeless powders, the manufacture lack powder has greatly decreased, and with it the use of potassium nitrate also decreased. 

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