Fireworks Chemistry – Start With a Bang, Add Some Color

Chemistry, Entertainment
Pyrotechnics, often called fireworks, has a long history dating back to the days of gunpowder (black powder), developed in 9th-century China. Whether it is a sizzle, an explosion, or a showy display of colorful lights and sounds, the chemical reactions involve oxidation/reduction (REDOX) chemistry. What Is Oxidation? Oxidation is essentially the removal of electrons. Consider a very simple example. An uncharged sodium atom (symbol: Na) has 11 negatively-charged electrons. The atom has no net charge, however, because in its center part or nucleus, there are 11 positively-charged protons. Sodium can lose one electron to form a positively-charged ion called a cation. Now we can look at this process as if it were a mathematical equation. If we have the number 4 and we wind up with the numbers 3 and…
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Acid-Base and REDOX (Oxidation-Reduction) Chemical Reactions

[caption id="attachment_19477" align="alignright" width="440"] Rocketry thrives due to REDOX reactions.[/caption] Acid-Base and Redox: When they can, chemists categorize chemical reactions into types. Some specialized varieties of chemical reaction include those named for specific individuals involved in their discovery. As examples, there are the Diels-Alder reaction, the Claisen rearrangement, the Dieckmann condensation, and the Friedel-Crafts alkylation. Yet, many chemical reactions can be classified simply as acid-base reactions, or as oxidation-reduction (REDOX) reactions. Consider examples of each... Acid-Base Reactions When I was young, I was deeply interested in rocketry. My parents bought me one of those red plastic rockets that included a pump. You partly filled the rocket with water, then pumped air into it until the pressure made it difficult to pump more. Then you aimed it upward and pushed a…
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Pyrophoricity: How Does It Work?

Chemistry, Physics
[caption id="attachment_3651" align="alignright" width="440"] Pyrophoric ferro-cerium striker[/caption] A substance exhibiting pyrophoricity (including certain metals) reacts quickly with oxygen, producing heat, and bursting into flames. Alkali metals are pyrophoric, but there are other pyrophoric metals as well, given the proper conditions. Otherwise, they are stable and may be put to a number of uses without fear of bursting into flame. The overall principle is a simple one: metals are electropositive. Oxygen is electronegative. Almost all metals will react with oxygen to some extent. As a metal oxidizes, the reaction releases a little heat energy. If the heat cannot dissipate, it builds up. This speeds further oxidation, increasing the heat yet more. The metal may burst into flames. Those “Other” Metals Some alkaline earth metals such as calcium, and a few other…
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