Use the granulated sugar and not the powdered sugar. Place the test tube in sand to protect the container from the extreme heat generated. Place one drop of concentrated sulfuric acid on to the mixture. When sulfuric acid is introduced heat is created which decomposes potassium chlorate to produce oxygen according to the equation below. Some of the products of the reaction are shown on the right. Black pieces of carbon can be seen inside the test tube.
Other products include carbon dioxide, water and of course heat. Do not store mixtures of sugar and potassium chlorate. Concentrated sulfuric acid is a strong dehydrating agent and should be handled carefully. Spills should be neutralized and wiped up. Disposal: Allow test tube and reaction products to cool. Soak in water and scrub to remove residue.
Residues can be flushed down the drain with water. Download a Printable Version. Molecular Structure, Bonding, Orbital Hybridization. Upon the addition of a drop of sulfuric acid, the chemicals react with each other, producing a tall purple flame, a lot of smoke, and a fairly spectacular explosion of the glass jar. The same demonstration is then repeated with a closer magnification. In the second video clip, the same chemicals are combined in a Pyrex beaker, with similar results.
I generally get the best results with this demo by using ordinary granulated table sugar or powdered confectioner's sugar. Reagent grade sucrose often consists of larger granules, and requires more sulfuric acid to get the reaction to sustain itself. When using confectioner's sugar, it is especially important to get a good mixing between the two chemicals, otherwise the finely powdered sugar can smother the fire. The tube can then be cleaned.
Solid carbon remaining in the tube can be placed in the trash. Part of the course requirements for the COSL is to select, plan, practice and perform a demonstration.
The procedure for the gummy bear demo was easy to follow. When I observed — after just a few short steps — the colorful dazzle of light, sound and smoke, I knew I wanted to perform this demonstration. It was decided during practice that we would use both potassium chlorate and sodium chlorate — respectively producing purple and yellow-colored flames. Dressed in spiffy blue chemistry outreach lab coats and safety goggles, we presented outside to a big semi-circle of more than three hundred excited kids and parents.
The excitement was infectious yet intimidating. The oohs, ahhs and applause that arose from the audience as the purple and yellow light, hissing sound, and smoky residue spewed from the tubes left us with big smiles.
It was all so fast and exciting; my heart was racing. To see a youngster so inspired and excited about science was my crowning moment of the night. I learned numerous lessons from this experience. First and foremost is to fully understand the chemical concepts. While I had created a poster display depicting the chemical equations, in the end I struggled with what the equations were communicating.
Second, stick to the plan and keep it simple. Using the two different chlorates interfered with my goal of the audience understanding the processes.
Third, do not rush when speaking.
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