Fireworks Term Paper Example | Topics and Well Written Essays - 1250 words

Fireworks - Term Paper Example Fireworks The properties of firework explosions are force, velocity and heat. The combusting components undergo rapid entropic change, and thus this lends to the term â€Å"firework explosion.† The forces produced are generated by the rapid evolution of gases and heat that force them to expand according to the combined gas law (PV/T=k) where p is pressure, V=volume and T is temperature. The force of explosion is a component of the gas pressure. It is exerted equally in all directions obeying Pascal’s principle. Therefore, P=F/A where the ‘A’ is the area of confined combustibles. The force is responsible for the launching of the fireworks, their dispersion velocity and sound (report). Heat is a consequence of combustion and exothermic reactions such as oxidation and thermite-like redox reactions with the firework. The total summation of the energies produced obeys the first law of thermodynamics by adhering to the basic principle of â€Å"conservation of energy† Fireworks are generally composed of three chemical compounds; a fuel, an oxidizer, color producing compounds, a chlorinator and a binder. Manufacture of the fireworks is mainly done using chemicals that are non-toxic. Some compounds though, elicit high reactivity and toxic properties if handled directly. As will also be seen in later sections, the reactive products given off some other compounds are toxic. The fuel is the main component that allows the fireworks to burn. It is composed of sulphur, carbon based compounds, or metals. Phosphorous is also added to some fireworks for its glow in the dark properties. The most common metals are aluminum and magnesium. These burn brilliantly and are therefore preferred to others such as titanium. They are also cheaper. Often, the alloy, Magnalium is used. This is because magnesium does not form a protective oxide coat. This can be directly attributed to its high reactivity and thus higher risk of uncontrolled combustion. It may also cause serious burns and blindness due to its characteristically high temperatures and brilliance on combustion. The oxidizer is the accelerant used to make the burn more intense and violent. Potassium compounds are mostly preferred for this purpose. They include the nitrates, perchlorate, chlorate and peroxides. The potassium ions may also impart a pink color to the flame. Direct contact with these compounds may ca use an oxidizer burn to human skin or any organic material. Not to mention the fire risk if exposed to already combustible organic materials such as cloth, natural gas or dry grass. The colour imparting compounds are mainly metals. Their cations are the main contributors of the color. Their anion compounds determine how brilliantly they burn. Examples are the chlorides and nitrates that enhance brilliance. Carbonates and oxalates reduce brilliance. This is also where the aspect of toxicity emerges. a) Infra-red color- rubidium nitrate- it is not directly toxic, but is capable of oxidizing compounds b) Silver/ white- antimony sulphide- exists as stibnite and the antimony pentasulphide. The pentasulphide is flammable and can have potentially toxic effects on reacting with strong acids such as HCl. The reaction produces hydrogen sulphide which is a potent nerve toxin. HCl is naturally found in the stomachs of many mammals as a component of gastric juice. The pentasulphide is thus poten tially harmful if ingested. The stibnite form is also potentially toxic c) Blue- copper arsenite- the compound is toxic, and this can be