Fireworks!!
● Fireworks are a type of explosive pyrotechnic device
● First recorded use was in ancient China and was used by emperors and empresses for various celebrations and festivals
● Used in modern times for the same purpose
● This experiment will explore the various physical and chemical components of the fireworks and the chemistry behind fireworks, specifically aerial shells
● Disclaimer: Fireworks are illegal in the state of New York, so do not
attempt to recreate or reproduce this experiment (unless you go to another state)
Physical Components of Fireworks
● Fireworks are made of several components
1. Break-It is final part of the firework. The material it is made out of determines the strength of the explosion. The stronger the material, the more pressure builds up and the stronger the explosion.
2. Time delay fuse-Determines when the firework will explode. It is ignited by the fuse and later ignites the break.
3. Stars-Clay dough like lumps made up of a mixture of oxidizing, reducing, coloring agents, and binders. The arrangement of stars determine the shape of the explosion.
4. Black Powder- Chemical explosive used to propel the stars and break in the air. Consists of sulfur, charcoal, and potassium nitrate 5. Launch tube- The apparatus in which the firework is held. Tightly
packs the components and creates pressure,
6. Fuse-Wires, where an electrical current in run through, creating a spark that lights the time delay fuse
● The pattern of the firework depends on the arrangement of the stars inside the shell.
● To create a certain shape, stars are arranged in that shape and surrounded by a break charge that separates them from the rest of the firework
Ex.
Components
Stars
Blackpowder
What are Sparklers?
●
Sparklers are a type of hand-held firework that
emits sparks and flames as it burns
●
Chemical components are the same as
fireworks, but materials are combined into a
slurry, and coated onto a metal wire.
●
There are five main components of fireworks
1. Fuel- Fuel, often black powder is combusted, and large amounts of energy is released propelling break and stars into the air. All fuels contain an organic compound
2. Oxidizing agents-Used the produce oxygen needed to burn mixture within fireworks. Commonly nitrates, chlorates and perchlorates; oxygen rich
compounds
3.Reducing Agents-Usually black powder, is used to react with the oxygen produced by the oxidizing agent. This produces hot gasses which creates the explosion in fireworks
4. Binders-Hold all the components of a firework together into a slurry. They do not work until the firework has been lit, because of the instability of the substance
5. Coloring Agents-Elements that give the firework the colors
Combustion and Reactions
● Oxidizing Reaction: Nitrates, perchlorates or chlorates are used because these compounds have a large amount of oxygen in them, which is used needed in order for the mixture inside to burn
Why are Fireworks different
colors?
● Manufacturers add different elements into firework mixtures to create various colors
● When elements are burned, electrons in the element are excited and jump to the next energy level in the atom. As the return to ground state, the electron releases the energy gained in the form on a photon that has a certain frequency. The difference of energy levels is unique to the element.
1. Combine four teaspoons of aluminum powder, one cup of potassium chlorate, and a pinch of charcoal in a container
2. Mix 200mL of water and 20mL of dextrin in a beaker
3. Add dextrin mixture to dry materials a little at a time and combine until a thick consistency similar to wet cement is attained
4. Divide mixture evenly into three separate containers
5. In one container, add four teaspoons of barium nitrate and in another add two more teaspoons of Aluminum powder
6. Dip twelve inch long iron wires into each mixture. 7. Let sparkers air dry overnight
8. Ignite
Baking Dextrin
Dextrin combined with water
Results of Experiment
Type of Sparkler Color Brightness Amount of "Sparkle"
Regular None None None
Barium Nitrate Red 1st 1st
Additional Aluminum
● The Barium Nitrate sparkler had to the most "sparkle" and was the brightest
● The sparkler that followed the original recipe, did not ignite
● Sparkler with a thicker coating worked (Barium Nitrate and Extra Aluminum) because there was more material to burn
1. All the sodium might have not been filtered off when the potassium chlorate was made
2. Additional dextrin was added to the dextrin and water mixture.
3. Measurements were not exact.
4. Aluminum powder was used instead of filings
Aluminum Powder: Potassium Chlorate:
Dextrin: Charcoal:
