Why is kclo3 used in fireworks

I generally get the best results with this demo by using ordinary granulated table sugar or powdered confectioner's sugar. Reagent grade sucrose often consists of larger granules, and requires more sulfuric acid to get the reaction to sustain itself. When using confectioner's sugar, it is especially important to get a good mixing between the two chemicals, otherwise the finely powdered sugar can smother the fire. This reaction often produces a great deal of smoke, and must either be done in a well-ventilated area, or in a working fume hood.

I've set off smoke alarms when doing this demo in hoods whose ventilation was under par. I've seen videos of this demonstration being done by dropping a source of sugar such as a piece of candy into a test tube containing molten potassium chlorate.

However, the one time I experimented with such a procedure using a candy cane for a sugar source , it resulted in a loud explosion which blew the bottom of the test tube to pieces, and I haven't been brave enough to try a repeat performance. Potassium chlorate is a powerful oxidizing agent; do not store the mixture of sugar and potassium chlorate since this can detonate unexpectedly.

The new, striking array of colors came from the spectral emissions of excited gas-phase molecules instead of from black-body radiation.

Many of these quaint color-burning formulas are beloved by old-school pyrotechnicians. But the mixtures of mercurous chloride, arsenic sulfide, copper acetoarsenite, and barium chlorate are unstable, and they are toxic to human health and the environment. In the past six to seven years, research scientists have also made much progress to devise more environmentally friendly fireworks. The colors of most modern fireworks involve a few metal chlorides, which fluoresce strongly in the visible wavelengths: Barium chloride produces green; strontium chloride produces red; and copper chloride produces blue.

These compounds by themselves are so hygroscopic that is, attractive to water that they render any mixture damp, unburnable, and even unstable. The solution has been to keep the metal and chlorine separated until showtime. A typical firework mixture consists of fuel, an oxidizer to provide the oxygen necessary for burning, and the color-producing metal- and chlorine-donating compounds.

The entire mixture is wetted down to bind it together and then cut into flammable chunks known as stars—the colorful dots of light that burst from a firework shell into the sky. Old books on pyrotechnics are chock-full of recipes for stars, formulas that enthusiasts have been continually refining. In fact, says John A. Conkling , former technical and executive director of the American Pyrotechnics Association and emeritus chemistry professor at Washington College in Chestertown, Md.

People use to make stars with potassium chlorate, KClO 3 , which serves as both an oxidizer and a chlorine donor. Nowadays, most star formulas use the more stable potassium perchlorate KClO 4. The metal-donating compounds often include barium nitrate, strontium carbonate or nitrate, sodium oxalate, and copper carbonate.

In the past few decades, colors have also gotten markedly more vivid—almost fluorescent and electric—thanks to the addition of the magnesium-aluminum alloy magnalium. Even blue, the most difficult color to produce, has evolved from an anemic bluish white to an honest-to-goodness azure. More seriously, lovers of fireworks have also had to grapple with the reality that the detritus, smoke, and chemical vapors that rain down during a fireworks show pollute the environment.

The U. Environmental Protection Agency now regulates perchlorate levels in water and soil. Metals in fireworks such as strontium and barium are toxic to human and animal health, and the burning process produces other harmful species such as polychlorinated hydrocarbons.

Pyrotechnic scientists have already begun to address some of these issues, says David Chavez , an explosives chemist at Los Alamos National Laboratory. Traditional firework shell casings, which are made out of cardboard, fall back to the ground. New casings, made from polymers such as hydroxyl-terminated polybutadiene, burn entirely. Scientists are also developing new ways to produce brightly colored but environmentally friendly flames.

A group led by Jesse Sabatini , an energetic-materials chemist at the U. Army Research Laboratory, has developed a green-burning compound that uses tris 2,2,2-trinitroethyl borate instead of barium. Over in Germany, a group led by Thomas M. Copper bromide, the researchers discovered, emits a brilliant blue without the use of chlorine compounds. Their flame formula includes copper bromate [Cu BrO 3 2 ] as an oxidizer and hexamine as a fuel.

These new color developments may take some time to enter mainstream commercial fireworks displays, but Sabatini says companies anticipating new regulations are cautiously receptive to the idea of using the new formulations, even if they cost more. Ironically, red flames, which were once the easiest to produce with toxic strontium compounds, are now the hardest to produce with environmentally friendly components.

Lithium, Sabatini says, is one possibility, but it also burns incandescently, emitting light of all frequencies, which washes out the red. When researchers do, there will certainly be cause for celebration—and perhaps a few crimson-colored fireworks.

Contact the reporter. Submit a Letter to the Editor for publication. Engage with us on Twitter. Because it is flammable and also an explosion hazard. Potassium is not present free in nature. It is present in various minerals like carnallite, langbeinite, kainite, and sylvite.

The minerals that contain the content of potassium are also termed as potash. In the periodic table, potassium is placed in the first column. Its atomic weight is The unit of measurement of the mass of an atom is atomic mass is AMU atomic weight unit.

Potassium is classified as an alkali metal that was discovered by Sir Humphry Davy in the year At room temperature, it exists in the solid-state. The density of potassium at room temperature is 0.

The melting point of potassium is around Potassium compounds potassium nitrate, potassium perchlorate, potassium chlorate, and many others are good oxidizing agents. These compounds on the exposure of air react fastly. Pure potassium is never used in firecrackers but, the compounds of potassium are used in them. If we talk about potassium nitrate KNO3 , it exists in the form of black powder.

And you may have noticed that many firecrackers contain black powder similar to potassium nitrate. Potassium nitrate is a mostly used oxidizer in large varieties of fireworks. These are used in spark effect stars firecrackers. Aluminum powder is also an important mixture of flash powder used in fireworks.

The balanced reaction of the fireworks containing a mixture of potassium nitrate black powder and aluminum powder. Potassium chlorate is also widely used powder in fireworks. This powder came into use in a mixture of fireworks as good colored flames were possible with this powder.

This helps in quality color composition. A few examples of firecrackers using this mixture are pull-string crackers, toy cap guns. It came into use in the mixture of flash powder as a replacement of potassium chlorate. The mixture containing potassium perchlorate is safer and due to which, they are largely used in the fireworks as an oxidizer. This powder has lesser sensitivity to ignition through friction or by an accidental impact.

The reaction of firework containing a mixture of this compound with aluminum powder is shown below. The stoichiometric ratio of content in this powder used in flash works is These salts are also commonly used in the manufacturing of fireworks due to the following reason:. Carbon : It acts as a fuel to the powder of firework.