A LEX C ABRERA S PENCER A LLEN R YAN M ILLER R EACTION C AR

Reaction Chemistry  NaHCO 3 (s) + HCl(aq)  NaCl(aq) + H 2 O(l) + CO 2 (g)  n=(PV)/(RT)=[(5atm)(.7 L)]/[(.0821 L-A/mol-K)(293 K)] n=.14 mol Thus, we want roughly.14 mol of each reactant  NaHCO 3 (s) + HCl(aq)(+20mL H 2 O) ~.14 mol 12.1M (84 g/mol) ~.14 mol ~12 g ~12 mL   NaCl(aq) + H 2 O(l) + CO 2 (g) ~.14 mol

Car Design  Original Design:

Car Design  Second design (significantly expanded back axel):

Testing Results  Initially we wanted to go the distance without spewing, but it became apparent that our car was not going to do that very easily. After three tries of it going 2-4 ft, we decided to turn it around and let it spew. This made a significant difference, as can be seen on the next slide. We then, however, encountered a problem with it tipping. We compensated for this by expanding the back axel. This stopped it from tipping and we were able to achieve acceptable results. There was very little variation from our measurements, as it seemed to be the design of the car that largely affected the overall outcome.

Data and Plots trial

Conclusion  Our redesigned back axel that saved us on the first day was not enough for the finals. The axel had become slightly more bent, and instead of going straight, the car regularly veered off to the left. If we could have (or would have) replaced the back axel with less bent pieces, I feel that the car would have come much closer to the desired distance. As it was, the car was inconsistent and very hard to predict.