In this demonstration we react 30% hydrogen peroxide (H2O2) with a catalyst sodium iodide (NaI). In this reaction oxygen gas (O2) is released in vast quantities very rapidly. We trap the oxygen gas using dish soap so that it comes out as massive form. We add food coloring to give it some interest. The form, when it oozes out of the narrow neck of the flask, resembles toothpaste being squeezed out! Be warned. This is not real toothpaste, so please do not eat it or taste it. Please do not try this experiment at home as it uses harmful chemicals at high concentrations.
In this experiment we use baking soda and sugar to create a cool black snake effect. Baking soda or sodium bicarbonate has a chemical formula of NaHCO3. When heated, it breaks down into three compounds including water (H2O) and carbon dioxide (CO2). The pressure from this gas pushes the carbonate from the burning sugar out of the sand, producing the ‘black sugar snake’.
To burn and sustain a fire we need three elements to be present at the same time: Oxygen (O2), Fuel, and Heat. Fuel could be any flammable materials like paper and wood. So, if we want to extinguish a fire, we need to remove at least one of these elements from the scene.
In this experiment we try to put out the flames on tea candles by ‘pouring’ carbon dioxide gas on to the flames.
How do we produce carbon dioxide? Easy. We can make our own container full of carbon dioxide by combing two chemicals found in our kitchen cabinets, namely baking soda and vinegar. When mixed, these two compounds go through a chemical reaction producing carbon dioxide. Carbon dioxide is heavier than air. So, it tends to fill the container. We can literally pour this gas out of the container on to the flames thereby displacing the much-needed oxygen from the flames. The result is that the flames go out in no time!
Why do you think dentists warn us against consuming excessive amounts of sugary food and beverages? It is because the sugary food feeds the bacteria in our mouths and produce acids. These acids can erode the protective enamel layer on our teeth giving rise to cavities!
In this experiment, we test how beverages of different acidity affect the teeth. Since we cannot find real teeth to do the experiment with, we used eggshells. Why? Because eggshells resemble the thin enamel coating on our teeth because they both have the same mineral structure.
When we think of Leonardo da Vinci what comes to mind is his famous paintings like Mona Lisa and Last Supper. But did you know that he was also a great sculptor, architect, and an engineer? He had designed an easy to assemble self-supporting bridge which we refer to as Da Vinci Bridge. In this demonstration, we show how to build a model da Vinci bridge using a stack of popsicle sticks and some rubber bands.