The Chemistry of Ostentatious Fireworks

The Chemistry of Ostentatious Fireworks

Tarek Aziz

A few days ago the final match of 12th edition of Cricket World Cup 2019 was held between New Zealand and England in Lord’s stadium, London, where the England football team clinched the title of the world cup. Certainly, you would see the grand celebration of the champions and the whole stadium was turned into a dreamland where ostentatious fireworks were being displayed for applauding the winning teams.

Photo: Victory celebration using fireworks

Not only in the celebration in the world cup but also you might be experienced about fireworks in the New Year celebration, Eid celebration, Wedding Ceremony, or even on your birthday celebration.

However, this ostentatious views of fireworks are nothing but chemistry and chemical reactions. In this article of Nucleus, we are going to make you master of the fireworks and let you know the function of the fireworks.

The fire was discovered by the patriarchal cavemen about half a million years ago rubbing pieces of wood but they did not know about the science of fire because they discovered that only for their natural demand. Interestingly, only 200 years ago, the human can interpret the fire as the source of energy and the luminous portion is nothing but hot gas. As much as human development was being occurred, human being endeavors to use fires in different aspects of life includes fireworks.

But it is still unclear that, when and how the fireworks were invented. A popular legend has that the fireworks were invented accidentally in a Chinese kitchen. While the cooked mix, charcoal, sulfur, and saltpeter, and burned in an enclosed space, exploded. Later, a good number of Indian, Chinese, Italian, Greek, German, and English Pyrotechnicians give the effort to develop the fireworks. In the mid-15th, the English, and in the mid-17th century, Europeans started to use fireworks for entertainment. Fireworks become popular in the United States during the 19th century, initially as a way of celebrating Independence Day on July 4th.

Basically, a firework is made of three sections, mortar, areal shell, and fast fuse. The main portion is the areal shell as all the lights, colors, and sounds of the fireworks come from this shell. The areal shell is made of explosive gunpowder, and small globs of material called stars.

Figure: Firework structure

Pyrotechnicians design each star with four chemical ingredients: an oxidizing agent, a fuel, a metal-containing colorant, and a binder. As we watch the beautiful colorations while exploded are nothing but the coloration of the stars. Different materials are used to bring the tasteful colors in fireworks, e.g., calcium compounds for orange, magnesium for white, strontium for red, copper for blue, sodium for yellow, strontium and copper for violet, etc. Pyrotechnicians use the combination of different compounds for bringing the different colors in fireworks.

Mortal shell helps to uplift the fireworks into the sky following the law of conservation of momentum and the fast fuse is a thread while it ignites, an explosion happens using this following simple chemical reaction and we observe the mind-blowing views of fireworks:

2KNO3 (potassium nitrate) + S (sulfur) + 3C (carbon in charcoal form) → K2S (potassium sulfide) + N2 (nitrogen gas) + 3CO2 (carbon dioxide)

Photo: The metal compounds for responsible colors of fireworks

Undoubtedly, fireworks give joy and pleasure, but they have to handle with utmost safety because they are extremely hazardous and might be a cause of causalities due to misfire or late-fire. Due to being the presence of hazardous chemicals, it affects the stability of the total environment too. 

References:

1.     The Chemistry of Fireworks (Second Edition)-Michael S. Russell

2.       Color lovers blog (Fireworks)

3.       Wikipedia (Fireworks and Mechanism)

4.       Photos are taken from different sources on the internet  

-Writer

Student of the Chemistry Department of Jahangirnagar University. He can be reached at tarekju45@gmail.com.