Chemistry of Fireworks

Matt ClarkeMrs. WrightChemistry 20

Introduction

Everyone enjoys a good fireworks show, but no one really knows the chemistry behind the big bangs and colourful explosions.

Fireworks are truly an amazing composition of chemistry invented by the Chinese

In origin, they were simple fire crackers but have now evolved into brilliant shows that light up the night sky

Ingredients for Combustion

In order for fireworks to achieve the effect they do, they must include six vital ingredients

1. Fuel 2. Oxidising Agents 3. Redusing Agents 4. Regulators 5. Coloring Agents 6. Binders

Fuel

Usually made up of black powder Used to set the chemical reaction of

the firework in actionChemistry point of view:o The fuel gives up the electrons to the atoms

within the oxidiser, resulting in the release of atoms from the oxidiser

o This forms a stable mixture that is easily combustable.

o When this mixture ignites it vaporizes and turns into a flame of ignition, therefore maximising the reaction of the oxidiser

Oxidising and Reducing Agents The Oxidising Agent is needed to produce the

oxygen needed to burn the mixtureo Usually made up of Nitrates, Chlorates and Perchlorateso Chlorates are better oxidisers for they give up more

oxygen molecules then Nitrateso Perchlorates produce even more oxygen than Chlorates,

but do not react as easily because they are more stable The Reducing Agent is needed to burn the

oxygen and produce hot gaseso Common reducing agents are sulfur and carbon. They

react with the oxygen to form sulfur dioxide and carbon dioxide

Regulators and Coloring Agents Regulators are used to control the speed of the reactiono This is done by adding different metals to the mixture. The more

surface area a metal has, the faster the reaction will happen Coloring Agents are used to add, obviously, the color to

the mixtureo This is achieved by adding different elements to the mixture:

Sodium- Orange/Yellow, Strontium-Red, Barium-Green, Copper-Blueo Also, the combining of elements can be done to create even more

color combinations: Strontium + Copper = Purpleo Sometimes metals, such as iron, steel, zinc and aluminum are

added. This adds the effect of sparks. This happens because the flakes of metals are heated to a high enough temperature to either burn or shimmer brightly

o When the different elements are heated by the hot gases surrounding them inside the firework, they produce these luminous colors

Binding Agents

The last component of a firework is the Binder

This is used to keep all of the different parts of the firework together in a consistent, paste like mixture

From Land to Sky [1]

It all starts with the lift charge The ignition of the black powder in a confined space

propels the mixture, as I previously stated earlier into the air to be ignited

The lift charge can propelthe firework as high as 1000 feet

From Land to Sky [2]

The fuse is a vital component of a firework

It ignites the black powder to launch the fire work, and also ignites the time delay fuse that will light the firework once air born

From Land to Sky [3]

The launch tube is considered to be one of the most, if not the most, important component of a firework.

If the packaged mixture does not fit perfectly in the tube, when the black powder

is ignited the energy will simply just escape the tube and not propel the package into the air

From Land to Sky [4]

Once the firework is air born, in a series of controlled explosions, it breaks a part releasing the different components resulting in a colorful explosion