The goal of this project, chemical dominoes, was to create a Rube Goldberg machine using chemical reactions to keep the "ball rolling" figuratively and literally. We incorporated reactions we had previously learned in chemistry and skills we had acquired in physics. Our first reaction was vinegar and baking soda to create gas, then we used hydrogen peroxide, yeast and dish soap to make elephant toothpaste, and finally our last reaction was to use Copper Chloride to dissolve aluminum and ultimately break the circuit therefore turning off a light, which was our end goal.
Sodium bicarbonate and acetic acid (vinegar and baking soda)
This was the first step in our chemical dominoes. It is triggered by us pulling a balloon, filled with sodium bicarbonate, over a flask containing acetic acid. Once the sodium bicarbonate falls into the acetic acid they react leaving a product of gas that fills the balloon which pushes a lever up which triggers the next
NaHCO3 + CH3COOH ---> CO2 + H2O + Na + CH3CO
Elephant Toothpaste
This step was started because the raised lever tilted the Hydrogen Peroxide into a cup of yeast, water, and dish soap. The warm water we used activated the yeast which served as a catalyst and therefore sped up the reaction. The soap created many small bubbles and all of the ingredients worked together to lift a cup filled with a small amount of copper chloride.
2H2O2 + Enzyme(yeast) ---> 2H2O + O2
Copper Chloride and Aluminum
The small amount of raising the cup did was enough to tip it onto aluminum foil which was a part in a circuit containing alligator clips, a 9 volt battery and an LED light. The copper chloride dissolved the aluminum foil therefore breaking the circuit and turning the light off. With that step our chemical dominoes was complete.
Sodium bicarbonate and acetic acid (vinegar and baking soda)
This was the first step in our chemical dominoes. It is triggered by us pulling a balloon, filled with sodium bicarbonate, over a flask containing acetic acid. Once the sodium bicarbonate falls into the acetic acid they react leaving a product of gas that fills the balloon which pushes a lever up which triggers the next
NaHCO3 + CH3COOH ---> CO2 + H2O + Na + CH3CO
Elephant Toothpaste
This step was started because the raised lever tilted the Hydrogen Peroxide into a cup of yeast, water, and dish soap. The warm water we used activated the yeast which served as a catalyst and therefore sped up the reaction. The soap created many small bubbles and all of the ingredients worked together to lift a cup filled with a small amount of copper chloride.
2H2O2 + Enzyme(yeast) ---> 2H2O + O2
Copper Chloride and Aluminum
The small amount of raising the cup did was enough to tip it onto aluminum foil which was a part in a circuit containing alligator clips, a 9 volt battery and an LED light. The copper chloride dissolved the aluminum foil therefore breaking the circuit and turning the light off. With that step our chemical dominoes was complete.
Reflection
I liked this project a lot and its a fun way to bring back a 9th grade project with an innovative and relative twist. I do wish we had more time than just a little over a week to build this though because I felt like our group went through a lot of trial and error that ate up a lot of our time. With this lost time we weren't able to fine tune our project to a point where it ran through perfectly. Our group was only able to get a "rough draft" of the mechanism; it was at a point where all the steps were sound but we hadn't got to a point where they actually triggered one another without help.