Hobbies And Interests
Background
As fans of sugar, children will be curious to learn about sugar's composition. The chemical composition for sugar is C12H22O11, meaning sugar is made of a combination of carbon, hydrogen and oxygen. Sulfuric acid combines hydrogen, sulfur and oxygen and is a toxic hazard that must be handled with care by adults only. It is interesting to note to children that the acid looks like water but is very dangerous. When sugar is mixed with sulfuric acid, the dehydration of sugar begins and the resulting reaction rips apart the bonds that hold the chemical composition of sugar together.
Experiment Setup
Safety is vital whenever doing experiments that involve sulfuric acid, and young children should not conduct the experiment independently. The experiment should be done as a demonstration in front of a group or in tandem with a child who can assist. Materials include a large wide-mouth beaker, a glass stem mixer, as little as 50 grams of sugar and 20 cubic centimeters of sulfuric acid. Before conducting the experiment you need to put on rubber gloves to protect your skin from sulfuric acid and goggles to protect from acid and sulfur fumes. Finally, the experiment should be performed in a well ventilated space with a fume hood over the beaker.
Running the Experiment
The experiment is essentially a three-step process. The beaker is set on a level surface, and sugar is placed inside. Next, the sulfuric acid is carefully dropped in the beaker on top of the sugar. The reaction begins immediately, with sizzling and heat being produced. Mixing the contents of the beaker with a glass stick expedites the process, and the contents of the beaker quickly transition to brown and then black. When the substance turns black, remove the mixing stick and place it in a nearby bucket of water to begin diluting the acid. The black contents in the beaker, carbon, rises without any further action from you.
What Is Happening
When sulfuric acid is mixed with sugar, the substance begins to rapidly dehydrate the sugar, removing or evaporating water. When water, which is made of hydrogen and oxygen, leaves sugar, one element remains: carbon. This is the black substance that appears in the beaker. The water evaporates because there is a large amount of heat produced and steam pushes the carbon vertically as it escapes, which is why the carbon rises. Sulfur oxide fumes are also produced, which are not safe to breath in enclosed areas. As an exercise in critical thinking, children can converse or reflect in writing about the difference between dehydration and drying.