Buzz
Chemical reactions are an integral part of our everyday experiences. From preparing meals in the kitchen to driving a car, these reactions occur around us constantly. This list focuses on some of the more fascinating and unique reactions that many of us have never witnessed. As my understanding of science is not all-encompassing, please feel free to inform me if any errors appear in my explanations, so I can correct them! Here are the top 10 extraordinary chemical reactions. Remember, these are not experiments to replicate at home (but if you do, share your video clips with us!).
10. Sodium and Water in Chlorine Gas
Sodium is an extremely reactive element, and when it comes into contact with water, it can result in an explosion. In this demonstration, a drop of water is introduced to a small piece of sodium inside a flask filled with chlorine gas. The bright yellow hue of the emitted light is characteristic of sodium's 'D lines', which is commonly used in street lighting. This reaction generates a considerable amount of heat. The combination of sodium and chlorine results in sodium chloride – or table salt.
9. Magnesium and Dry Ice Reaction
Magnesium is highly flammable and burns with an intense brightness. In this demonstration, magnesium is ignited inside a shell of dry ice – solid carbon dioxide. Magnesium can burn even in the presence of carbon dioxide and nitrogen. Due to its brilliant light, magnesium was historically used in photographic flashes and continues to be used in marine flares and fireworks.
8. Potassium Chlorate and Candy Reaction
Potassium Chlorate is a compound made up of potassium, chlorine, and oxygen. It is commonly used as a disinfectant and in the manufacture of fireworks and explosives. When potassium chlorate is heated to its melting point, anything added to it can cause a rapid and violent reaction, often resulting in an explosion (as demonstrated in the video). The gas released from the potassium chlorate is oxygen. This characteristic makes it valuable in environments like airplanes, space stations, and submarines, where it serves as a source of oxygen. A fire aboard the Mir space station was linked to this substance.
7. Meissner Effect
When a superconductor is cooled below its transition temperature, it becomes diamagnetic, meaning it is repelled by magnetic fields rather than attracted to them. This discovery by Meissner led to the concept of frictionless transportation, where objects could be 'floated' along a track instead of being physically connected by wheels.
6. Sodium Acetate Super Saturation
When sodium acetate is heated and then cooled, it becomes supersaturated in water. Upon contact with another object, it quickly re-crystallizes. This reaction also produces heat, making it useful for heat pads. Sodium acetate is commonly used as a preservative and contributes to the distinct flavor of salt and vinegar chips. In food, it is often labeled as E262 or sodium diacetate.
5. Superabsorbent Polymer
Superabsorbent polymers, also known as hydrogels, have the remarkable ability to absorb large quantities of liquid compared to their own weight. This characteristic makes them ideal for the production of diapers, incontinence garments, and other applications requiring liquid protection, such as underground cabling.
4. Floating on Sulfur Hexafluoride
Sulfur Hexafluoride is a colorless, odorless, non-toxic, and non-flammable gas. Being more than five times denser than air, it can be poured into open containers, allowing lightweight objects to float on it as if it were water. Another interesting application of this harmless gas is its inhalation; when breathed in, it significantly lowers the pitch of your voice – the exact opposite effect of helium. You can see this effect in action here:
The reason your voice deepens when you inhale sulfur hexafluoride is that its density slows the sound waves in your vocal tract, reducing their speed to just below half of the speed of sound. Helium, on the other hand, does the opposite.
3. Briggs-Rauscher Reaction
The Briggs-Rauscher reaction is a fascinating oscillating chemical reaction. As described on Wikipedia: 'The freshly prepared colorless solution slowly turns amber, then rapidly changes to a dark blue. This gradually fades back to colorless, and the cycle repeats about ten times in the most common version, eventually ending with a dark blue liquid that strongly smells of iodine.' This occurs because the first reaction releases certain chemicals into the liquid, which then trigger a second reaction, and this loop continues until the chemicals are depleted.
2. Thermite and Liquid Nitrogen
Thermite is a mixture of aluminum powder and a metal oxide that triggers an aluminothermic reaction, also known as the thermite reaction. While it is not explosive, it can produce brief but extremely high temperatures. A thermite reaction is initiated using a detonator and can burn at temperatures reaching thousands of degrees. In the video above, you can observe an attempt to 'cool' the thermite reaction by submerging it in a vat of liquid nitrogen.
1. Superfluid Helium
When helium is cooled to -271°C, it reaches the lambda point. At this point (as a liquid), it is referred to as Helium II. Helium II is a superfluid, meaning it has no measurable viscosity even when flowing through capillaries with widths as small as 10?7 to 10?8 meters. Additionally, it exhibits the curious property of creeping up the sides of a container, seemingly defying gravity, in search of warmer areas. Watch the clip above to witness this incredible phenomenon!
