Event 3: Chemical
Engineering
Chem-E-Car
River Dell High School Team A (RDHSA)
Celyne Moh
Daniel Ross
Ronald Vertsman
Objective
“Design and construct a car that is powered
with a chemical energy source that will travel
a given distance and stop. ”
• Commercial batteries (for example, AA batteries)
are allowed as the power source if a controlled
chemical reaction is used elsewhere in the car’s
system (as a stopping mechanism, for example).
Concept
• Iodine clock reaction
• Using a light and photo-sensor to control a
motor
Kinetics
Iodine clock:
Step 1:
IO3− (aq) + 3 HSO3− (aq)  I− (aq) + 3SO42− (aq) + 3H+ (aq)
Step 2:
IO3− (aq) + 5 I− (aq) + 6 H+ (aq)  3 I2 (aq) + 3 H2O (l)
Step 3:
I2 (aq) + starch  {a dark blue iodine/starch complex}
Rate = k[NaHSO3]2[KIO3]1
k = 188.04
Allocation of Budget
Item
Price
100g Potassium Iodate
$17.01
500g Sodium Bisulfite
$9.70
500g Starch, Reagent Soluble
$55.60
AAA batteries (20 Batteries)
$7.07
Distilled Water (3 Bottles)
$2.64
Total
$92.02
Construction
• Old RC car
• Fiberglass Cylinder
• Plexiglas©
• Batteries
• Copper wiring
• Circuitry
Circuitry
Kinematics
• Photo-sensor
• Colors of solutions
Distance Traveled = velocity x time
The proper concentrations for the reactants is
determined so the car travels a given distance.
Conclusion
• Car veers too much
o Axle
• Time of trial varies = distance varies
o Concentration of solutions
o Human Error
o Splashing
Reconstruction
nd
(2
• Car veering
o Replace axle
o Replace wheels
• Varying distances
o countdown
model)
Observations
nd
(2
model)
• Car veered less
• Car ran varying distances
Results
nd
(2
model)
Distance (feet)
40
35
30
25
20
15
14
15
16
17
18
mL NaHSO3
19
20
21
Conclusion
nd
(2
model)
• Car Veering
o The axle
• Varying distances
o Momentum
o Countdown
Reconstruction
rd
(3
model)
• Front wheel
• Reduce concentration of solutions
• Change variable reactant
• Cork
• Syringe
Observations
rd
(3
• Car runs straight
• Trials are more precise
• Trials are more accurate
• Solutions are not spilling
model)
Final Conclusion
• Car stops within 5ft of destination
• Car runs too fast for complete accuracy
Questions?