1. Reaction Powered Car By Josh Breen, Andrew Jeske, and Margaret Schneider CBE 101 Dec. 7, 2009

2. The Team From Left to Right: Andrew, Josh, and Margaret

3. The Reaction Our Initial attempt for propelling our car was to use Alka-Seltzer and water: C 6 H 8 O 7(aq) + 3NaHCO 3(aq) → 3H 2 O (l) + 3CO 2(g) + Na 3 C 6 H 5 O 7(aq) This reaction was not able to create enough pressure to propel the car with a reasonable amount of materials. Next, we tried with baking soda and vinegar: NaHCO 3(s) + CH 3 COOH (aq) → NaCH 3 COO (aq) + H 2 O (l) + CO 2(g) However, the amount required to make our car move caused our car to spew Finally, we tried using HCl and baking soda: NaHCO 3(s) + HCl (aq) → NaCl (aq) + H 2 O (l) + CO 2(g) This propelled our car without any spewing. Calculations A sample calculation using 12 M HCl and excess baking soda: 12 mL HCl (1 L/1000 mL)(12 moles/1 L)( 1 mole CO 2 / 1 mole HCl)= 0.144 moles CO 2 Now we calculate the pressure in the 0.7 liter bottle: P=(nRT/V)=(0.144 moles CO 2 *0.08205 (L*atm/K*mol)*293 K/0.7 L)= 4.95 atm Since the 0.7 liter propel hold 5 atm, we chose to use 12 mL of HCl and excess baking soda as the amounts to initially test our car with.

4. The Design Bottle tilted at 6 degree angle for minimal spewage! X cross beams in base plates for extra support! 2 adjustable bars on top for minimum wiggle! Rotating front axle! Stationary rear axle! Spacers around wheel for minimal friction School spirit for awesomeness!

5. The Results Trial #HCl (mL)Baking Soda H 2 O (mL)Distance (ft.) Spew 112excess1012yes 212excess05no 315excess07no 415excess05no 515excess05no

6. Conclusion Our car managed to move off the starting line without spewing, but it did not get very close to the target range of 25 feet. Our best non- spew distance was 7 feet. We made it closer while spewing, and we could have gotten much farther while spewing, but we settled for a shorter, non-spewing distance. If we were to try this experiment again, we could do much better even with a non-spewing car if a few modifications were made to our present car. We could lower the bottle angle so that our car would get more distance out of the same amount of reaction. The rear axle could be made to rotate to decrease friction. The whole car could be lowered down and made to have less air resistance. We could add an attachment to the nozzle so that there would be a smaller cross sectional area. Then we could add some sort of quick release valve so pressure wouldn’t be wasted while we spend time turning the nozzle on the propel bottle. There is also room for experimentation of different chemical reactions that may be more efficient.