1. By Cameron Oden, Shannon Cahill-Weisser, and Melissa Simpson CBE 101 8 th Annual Reaction Car Competition

2. Reaction Chemistry Hydrogen Peroxide & Pyrolusite Chemical Equation: H ₂ O ₂ (aq) + MnO ₂ (s) → H ₂ (g) + O ₂ (g) + MnO ₂ (s) Pressure: (.020 L)(8 mol/L)(1 mol H ₂ O ₂ /1 mol H ₂ ) = 0.08 moles H ₂ & 0.08 moles O ₂ P = [(0.16 mol)(0.08205 L-atm/mol-k)(293 K)]/(.700 L) = 5.5 atm We did not use this reaction because when we tested it, the gas was not produced quickly enough to be efficient for running the car. Hydrochloric Acid & Baking Soda Chemical Equation: HCl (aq) + NaHCO ₃ (s) → NaCl (aq) + H ₂ O (l) + CO ₂ (g) Pressure: (0.012 L)(12.1 mol/L)(1 mol HCl/1 mol CO ₂ ) =.1452 moles CO ₂ P = [(.144 mol)(0.08205 L-atm/mol-K)(293 K)]/(.700 L) = 4.99 atm We also added 12.5-13 mLs of water to help the reaction.

3. Car Design We ended up with a great design, but to arrive there, we had to rebuild the entire car from scratch. (The old design would run only 15 feet at the most) Here’s a work in progress: very close to the final design.

4. Test Results During our open lab time, while we tested different reaction ideas and different car ideas, our data was very inconsistent. We found that a simple change in the nozzle makes the difference between a car that curves vs. a car that runs straight. We also discovered that miniscule changes in amounts of water to our reaction impacted our results in a major way. With no water added, the car would travel ten feet at the most. When we added 12mLs of water, on average, the car traveled about 21 feet, and with 13mLs of water, the car traveled close to 25 feet on average. Open Lab TestingSemi-finals and Finals Semi-finals (3 rd Place) HCl (mL) NaHCO 3 (g) H 2 O (mL) Distance (ft)Comments Semi- Finals 121312.520'veered towards the right into the grass 23' 7" 20' 121312.7519' 1" 1213 ?kim wipe got stuck in nozzle 20' 2" 26' 10" Finals HCl (mL) NaHCO3 (g)H2O (mL) Distance (ft) Finals 121312.522' 3'' 1326' 8'' 12.7524' 5'' NO SPEW!!!

5. Conclusions During the semi-finals and finals section of this project, our car performed very well. It was also fairly consistent. During the finals we consistently ran between 22 and 27 feet. We learned that changes in volumes of water as small as 0.5mLs can make a difference in distance of around four feet. At the end of this project, our car was at its best. Without using different materials, we wouldn’t have been able to make the car more efficient or reliable. For people who’s cars weren’t running efficiently, keep in mind: Check the nozzle (cap) Make sure the car is sturdy Make sure the wheels are aligned