Chemistry of Fireworks

1. Matt Clarke Mrs. Wright Chemistry 20 Chemistry of Fireworks

2. 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

3. 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

4. Fuel • Usually made up of black powder • Used to set the chemical reaction of the firework in action • Chemistry point of view: • The fuel gives up the electrons to the atoms within the oxidiser, resulting in the release of atoms from the oxidiser • This forms a stable mixture that is easily combustable. • When this mixture ignites it vaporizes and turns into a flame of ignition, therefore maximising the reaction of the oxidiser

5. Oxidising and Reducing Agents • The Oxidising Agent is needed to produce the oxygen needed to burn the mixture • Usually made up of Nitrates, Chlorates and Perchlorates • Chlorates are better oxidisers for they give up more oxygen molecules then Nitrates • 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 gases • Common reducing agents are sulfur and carbon. They react with the oxygen to form sulfur dioxide and carbon dioxide

6. Regulators and Coloring Agents • Regulators are used to control the speed of the reaction • 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 mixture • This is achieved by adding different elements to the mixture: Sodium- Orange/Yellow, Strontium-Red, Barium-Green, Copper-Blue • Also, the combining of elements can be done to create even more color combinations: Strontium + Copper = Purple • 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 • When the different elements are heated by the hot gases surrounding them inside the firework, they produce these luminous colors

7. 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

8. 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 propel the firework as high as 1000 feet

9. 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

10. 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

11. 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