Stoichiometry Project

Stoichiometry of Airbags Project

In this project, we researched the importance of airbags, how they are made, and brainstormed idea on how to make an airbag, or something similar, on our own. Just like airbags, our product needed to inflate as right on impact, so while brainstorming, we needed to make sure the design would allow that. We also needed to have the bag inflate completely, so we needed to find the right mixture of chemicals to make sure the bag was completely inflated at impact.

So, our question was How much Sodium Bicarbonate (NaHCO₃) and Acetic Acid (HC₂H₃O₂) does it take to fill a sandwich size Ziploc bag with Carbon Dioxide (CO₂)?

Because the chemicals in airbags are toxic, and can be extremely dangerous to humans if touched or inhaled, why replaced them with safer substances that most people would have at home. We used sodium bicarbonate (NaHCO₃), also known as baking soda, and acetic acid (HC₂H₃O₂), or white vinegar, to make our chemical reaction. The outcome the mixture would create carbon dioxide (CO₂), which would inflate the bag, sodium acetate (NaC₂H₃O₂) , and water (H₂O). Here the chemical equation:

NaHCO₃ + HC₂H₃O₂ → CO₂ + H₂O + NaC₂H₃O₂

We decided to design an inflatable pillow that you could bring with you in the car, or wherever you needed it. We then did different trials to decide how much sodium bicarbonate and acetic acid it would take to fill a Ziploc sandwich bag (which is 6 1/2 inch x 5 7/8 inch). We did two separate trials, one having a constant amount of sodium bicarbonate, and one with a constant amount of acetic acid. While conducting the trials, we discovered that having an equal 1 to 1 ratio of sodium bicarbonate and acetic acid in tablespoons caused a reaction, but barely inflated the bag, and same with having more sodium bicarbonate than acetic acid. We discovered that having a 1 to 4 ration of sodium bicarbonate and acetic acid filled up that bag completely using the least amount of materials, so we used 1 tablespoon of sodium bicarbonate and 4 tablespoons of acetic acid in our product.

Knowing how much sodium bicarbonate and acetic acid we were going to use, we wanted to know how much carbon dioxide gas was going to be in the bag when it was fully inflated. So, we put together an equation to get us from tablespoons of acetic acid to litters or carbon dioxide gas. Here is that equation:

We were able to come to a conclusion that it takes 14.175 grams of Sodium Bicarbonate (1 tablespoon) and 56.7 grams of Acetic Acid (4 tablespoons) to fill a sandwich size Ziploc bag with Carbon Dioxide, which is .83 L of CO₂ was the answer to our question.

Stoichiometry: The study of the quantitative relationships or ratios between two or more substances undergoing a physical change or chemical change (chemical reaction).

Limiting Reactant: A reactant that is totally consumed when the chemical reaction is completed. The amount of product formed is limited by this reagent, since the reaction cannot continue without it.

The limiting reactant in our project was the acetic acid, because if you didn't have enough of it, the sodium bicarbonate would not completely dissolve and what was left over was left at the bottom of the bag.

Balancing Equations: When you are balancing equations, you make sure that there is an equal amount of what products that you used and what the reaction made.

Our balanced equation: NaHCO₃ + HC₂H₃O₂ → CO₂ + H₂O + NaC₂H₃O₂

As you can see, there is 1 Na (sodium) on each side of the arrow, 5 H's (hydrogen), 3 C's (carbon), and 5 O's (oxygen) on each side, meaning this equation is balanced.

Reflection:

I think I was a good communicator in my group. I did a great job making sure everyone knew what they were working on, and I also made sure that I was sharing what I was working on so that the entire team was on the same page. I also think I was a great collaborator. As a group, we were able to share ideas and the work load, and to the best of our ability on Zoom, we were able to work together throughout the assignments and the project.

I think one thing that I need to work on for my next project is critical thinking. I was having a hard time thinking of out of the box idea for the project when it came to design ideas, so working on being more creative when coming up with designs for the next project will benefit myself and the group. Another thing I need to work on is showing my character. Although I did take a leadership role in my group, I need to work on being more personable with my group members. I know that this is hard on Zoom, but that means I need to work even harder to make my character more noticeable.