It is common for science textbooks to contain statements like “energy is stored in chemical bonds” or “energy is released when the chemical bonds in glucose are broken.” These statements can lead to the misconception that energy is stored when chemical bonds form and is released when the bonds are broken. In fact, the opposite is true. Just as it takes energy to pull two magnets apart, energy must be absorbed to break the bonds holding atoms together. Energy is then released when new bonds form.
These concepts are explored in the brand-new Reaction Energy Gizmo. In the Gizmo, students examine simple chemical reactions such as the synthesis of water and the combustion of methane. Using a set of mechanical claws, students break up the bonds holding the reactants together and measure the energy absorbed in this process. Students then create the product molecules and measure how much energy is released. If more energy is released than absorbed, then the reaction as a whole will be exothermic. If more energy is absorbed than released, the reaction is endothermic.
The Reaction Energy Gizmo was designed for high school chemistry students and explores enthalpy, thermochemistry, and Hess’s law. We hope you enjoy the new Gizmo!