Last updated on July 23rd, 2020 at 05:24 am
Chemistry has always been a fancy subject when it comes to experiment and observations. Here is a collection of some of the mind-blowing experiments and the theory behind their fancy observations.
The experiments demonstrated in the videos –
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Belousov–Zhabotinsky reaction or BZ reaction, is one of a class of reactions that serve as a classical example of non-equilibrium thermodynamics, resulting in the establishment of a nonlinear chemical oscillator. The only common element in these oscillators is the inclusion of bromine and an acid. The reactions are important to theoretical chemistry in that they show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior. These reactions are far from equilibrium and remain so for a significant length of time and evolve chaotically. In this sense, they provide an interesting chemical model of nonequilibrium biological phenomena, and the mathematical models of the BZ reactions themselves are of theoretical interest and simulations.
- Luminol (C8H7N3O2) is a chemical that exhibits chemiluminescence, with a blue glow, when mixed with an appropriate oxidizing agent. Luminol is a white-to-pale-yellow crystalline solid that is soluble in most polar organic solvents, but insoluble in water. When luminol is sprayed evenly across an area, trace amounts of an activating oxidant make the luminol emit a blue glow that can be seen in a darkened room. The glow only lasts about 30 seconds, but investigators can document the effect with a long-exposure photograph. Crime scene investigators must apply it evenly to avoid misleading results, as blood traces appear more concentrated in areas that receive more spray. The intensity of the glow does not indicate the amount of blood or other activator presents, but only shows the distribution of trace amounts in the area.
- Sulphuric Acid and Sugar – The sulfuric acid removes water from the sugar in a highly exothermic reaction, releasing heat, steam, and sulfur oxide fumes. Aside from the sulfurous odor, the reaction smells a lot like caramel. The white sugar turns into a black carbonized tube that pushes itself out of the beaker. Sugar is a carbohydrate, so when you remove the water from the molecule, you’re basically left with elemental carbon. Carbon, of course, is black. The dehydration reaction is a type of elimination reaction.C12H22O11 (sugar) + H2SO4 (sulfuric acid) → 12 C (carbon) + 11 H2O (water) + mixture water and acidAlthough the sugar is dehydrated, the water isn’t ‘lost’ in the reaction. Some of it remains as a liquid in the acid. Since the reaction is exothermic (heat-generating), much of the water is boiled off as steam.
- Thermite is a pyrotechnic composition of metal powder, which serves as fuel, and metal oxide. When ignited by heat, thermite undergoes an exothermic reduction-oxidation (redox) reaction. Most varieties are not explosive but can create brief bursts of heat and high temperature in a small area. Its form of action is similar to that of other fuel-oxidizer mixtures, such as black powder. Thermites have diverse compositions. Aluminum is common because of its high boiling point and low cost. The reaction, also called the Goldschmidt process, is used for thermite welding, often used to join rail tracks. Thermites have also been used in metal refining, disabling munitions, and in incendiary weapons. Some thermite-like mixtures are used as pyrotechnic initiators in fireworks.
- The Briggs–Rauscher oscillating reaction is one of a small number of known oscillating chemical reactions. It is especially well suited for demonstration purposes because of its visually striking colour changes: the freshly prepared colourless solution slowly turns an amber colour, suddenly changing to a very dark blue. This slowly fades to colourless and the process repeats, about ten times in the most popular formulation, before ending as a dark blue liquid smelling strongly of iodine. Elephant’s toothpaste is a foamy substance caused by the rapid decomposition of hydrogen peroxide by using potassium iodide as a catalyst. How rapidly the reaction proceeds will depend on the concentration of hydrogen peroxide. Because it requires only a small number of ingredients and makes a “volcano of foam”, this is a popular experiment for children to perform in school or at parties; the experiment is also known as the “marshmallow experiment”, but isn’t related to the psychological Stanford marshmallow experiment.
- A single-displacement reaction, also known as a single-replacement reaction, is a reaction by which one (or more) element(s) replaces an/ another element (s) in a compound. It can be represented generically as A + B-C → A-C + B. Copper displaces silver in a solution when a copper wire is dipped in a silver nitrate solution, and solid silver precipitates out. In the activity or reactivity series, the metals with the highest propensity to donate their electrons to react are listed first, and the most unreactive metals are listed last. Therefore, a metal higher on the list is able to displace anything on the list below it.
Video Courtesy – ” Hybrid Librarian “
- Exploding gummy bears is an experiment best suited for high school students in a chemistry lab. Potassium chlorate is required for this experiment so caution must be exercised. For this experiment, students will need a test tube with a holder, a gummy bear, latex gloves, tongs, 10 grams of potassium chlorate and a torch. The potassium chlorate is added to the test tube. The test tube should then be placed in the test tube holder. Using the torch, the experimenter heats up the potassium chlorate until it is melted and bubbling. Using the tongs, carefully place the gummy bear into the test tube and quickly move your hand out of the way. Standing approximately two feet from the test tube is advised. The gummy bear will react very explosively with the potassium chlorate as the sucrose breaks down and oxidizes. The potassium chlorate is extremely hot and will cause burns to the skin so keep all body parts away from the testing area once the bear has been placed and until the explosion has ended.
- Golden Rain Experiment- Slowly adding the lead nitrate solution to the potassium iodide solution produces beautiful yellow swirls that dissipate and redissolve as the lead iodide spreads and dilutes.Next, quickly add the remainder of the lead nitrate. The tiny crystals of lead iodide that form swirl beautifully in the flask and the concentration gradients combine to generate an effect that looks like the atmosphere of a glittering gas giant. It really is impressive to see.The precipitate can be recrystallized to form more homogeneous crystals. Place the flask in some water at 60–70°C and all the crystals should dissolve – any traces of cloudiness can be removed by the addition of a few more drops of acid. As the water cools, stunning golden hexagonal crystals of lead iodide begin to crystallize to give the ‘golden rain’ effect. This process can take an hour or more, so return to the flask later in the lesson or have a pre-prepared sample to hand. The crystals are best viewed under a collimated light source, such as an overhead projector.
- Paroah’s Snake – This is an extremely simple firework demonstration. All you need to do is ignite a small pile of mercury(II) thiocyanate, Hg(SCN)2. Mercury thiocyanate is an insoluble white solid which can be purchased as a reagent or can be obtained as a precipitate by reacting mercury(II) chloride or mercury(II) nitrate with potassium thiocyanate. All mercury compounds are toxic, so the demonstration should be performed in a fume hood. Typically the best effect is obtained by forming a depression in a shallow dish full of sand, filling it with mercury(II) thiocyanate, lightly covering the compound, and applying a flame to initiate the reaction.
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Akshat Mishra is currently pursuing his doctoral degree in Physics from Lund University in Sweden. He feels the need to explore the depths of the not-so-dark universe while at the same time watch the quanta in action. Electronic Music is what puts him in the thinking zone.
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Akshat Mishrahttps://www.scilynk.in/author/akshat/
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Akshat Mishrahttps://www.scilynk.in/author/akshat/
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Akshat Mishrahttps://www.scilynk.in/author/akshat/
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Akshat Mishrahttps://www.scilynk.in/author/akshat/
