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Results: This project has unearthed many interesting findings. Besides the extreme
complexity of the fuel cells, many of the parts can’t be made at home.
Because of difficulty at finding parts for the zinc-air fuel cell the project
evolved from a building project to more of an experimental research project.
All and all, the project is different, but still interesting. Although the results
may not be as obvious as previously thought, it will be just as interesting
as the other.
In the new project, hydrogen fuel cells, I have been experimenting on a small
hydrogen fueled car. A book that came with the car has many interesting experiments
that I have been doing. During the course of this project I have learned a lot
about the research aspect of projects. Because I could not find any kits or
parts to use to build a zinc air battery I was force to do hydrogen instead.
Although I was unsure at first, the fuel cell kit that we purchased ended up
to be helpful, and fascinating to watch. The book that came with the car had
thousands of facts and experiments. In the end, the project has been a learning
experience to me, and may help in the years to come.
In the next lines I have documented the experiments and findings.
Experiment 1
Objective: Build and test “jar battery”
Materials: Glass jar, zinc cathode, copper anode, voltmeter, safety goggles
Chemicals: Potassium hydroxide (KOH), Water (H20), zinc powder (Zn)
Process: Before starting with the work, I put on the safety goggles. Once all
the materials were collected, I poured 6oz of water into the jar. Then placing
the copper and zinc strips into the jar I attached the voltmeter connecters
to the tops. After taking readings, I added about a spoonful of potassium hydroxide
to the water. Making sure to check the voltmeter, I then added a spoonful of
zinc powder. After waiting for it to settle, I stirred the solution and took
readings with the voltmeter.
Results: The jar with only 6oz water had a voltage of .868v. When the contacts
were reversed the battery had a reading of -1.127v. When the potassium hydroxide
was added it brought the voltage down to .544v. After waiting for a while, the
voltage went up to a max of 1.40v. Adding the zinc powder brought the voltage
down to 1.007v. Stirring the battery brought up the voltage to 1.012v. After
letting the battery settle, the voltage came down to .5v and later .8v. 24 hours
later the voltage came up to .9v. 48hours later the battery had a voltage of
1.07v.
Observations: Adding the potassium hydroxide to the water had an unexpected effect. After appearing to dip down in voltage, the battery slowly gained voltage as the potassium hydroxide mixed with the water. Once the potassium hydroxide was completely mixed, the voltage seemed to come to a halt. Adding the zinc powder seemed to do almost nothing. After slowly mixing it into the solution, the voltage slowly dipped down and came to a halt. Stirring the battery caused air to mix with the solution and brought the voltage up for a short amount of time. The air also caused it to fizz. 24 hours later, the battery was still fizzing and the voltage had gone up. 48 hours later the voltage had gone up yet again much to my surprise.
Experiment 2
Objective: Dissect zinc-air battery
Materials: 8.4 volt zinc-air medical battery, razor knife, saw, needle nose pliers, safety goggles, glass slide
Process: After putting on the goggles I placed the battery on a flat surface. With the razor knife I cut long grooves down the top edge of the battery. Once the grooves were deep enough, I took the saw and cut the top off the battery. After placing the removed top onto a glass slide, I carefully pulled one of the mini batteries from inside the case. Placing the battery case to the side, I then carefully cut the mini battery in half with the saw. After this, I removed the pieces from one half of the mini battery and placed them separately.
Results: Once taken apart, the battery looked much different than I had anticipated. Inside the outer case of the battery were six smaller batteries hooked together in series. The two pins that were visible without dissection were actually hooked to the ends of the string of batteries. Inside the mini battery consisted of: an anode and cathode separated by a gasket; a small screen, grey powder, and an extremely fine membrane, and a small piece of foam.
Observations: The plastic coating on the outside of the battery was much harder to take of than I expected. The plastic was obviously designed to be strong and tight fitting to prevent water damage and breakage. The batteries inside the case were firmly soldered in place and were hard to move. I was forced to pull out the entire chain of batteries to get just one out. Sawing the battery in half proved to be easy, but damaged the internal pieces. Once the two halves were on the table it was very hard to see anything in the grey powder. After staring at it for a while I finally saw something. After seeing the screen the rest of the parts seemed to appear.
Experiment 3
Objective: Construct model solar car
Materials: car body, motor, 2 axles, 4 wheels, solar panel, wires
Process: After assembling all the parts, I attached the axles to the body. One axle went directly onto the car while the other was attached to the motor. The motor was attached to the body of the car with a screw. With the axles in place, I then attached the wheels the ends. Then I fit the solar panel onto the body of the car and attached the wires to the wires of the motor with the help of junction boxes.
Results: With the help of a desk lamp the motor moved slowly. After changing the bulb to a higher wattage the motor moved faster.
Observations: The process went smoothly enough except for one broken wire.
One of the thin wires attached the motor broke off on the end and had to be
soldered. When the process was complete, the weather was too bad to use the
sunlight. With a desk lamp I tested the car and proved that the solar panel
and motor were working. Because the 40 watt bulb in the lamp wasn’t bright
enough, I switched it with a 100 watt one. After the bulb change, the car ran
much faster.
Experiment 4
Objective: Test response of solar car
Materials: solar car (already assembled), lamp with adjustable switch
Process: First I took the car and held it away from the lamp. Then I steadily moved it closer until it was as close as I could take it. Using the switch on the lamp, I turned up the brightness gradually.
Results: The car motor steadily sped up as the solar panel drew closer to the lamp. Turning the light intensity up caused the car to speed up quickly.
Observations: The car motor barley moved until it was directly in the light. As the light intensity increased, the motor sped up.
Experiment 5
Objective: Measure short circuit current and no-load voltage
Materials: solar car, multimeter, lamp, bulbs (60watt and 100watt)
Process: First, I disconnected the motor wires so that only the solar panel was attached to the car. Then after setting the multimeter to miliamps, I plugged it into the car. Then with the car on the table I turned on the lamp illuminating the solar panel and took readings. Next, I changed the multimeter to measure volts and repeated the procedure of measuring. Next, I changed the bulb and measured both again.
Results: The multimeter read the short circuit current as .25 for a 60watt bulb. The no-load voltage for the car with a 60watt bulb was .40 and for a 100watt bulb 3.5.
Observations: The measurements went well enough except for a problem with the lamp moving that made me start over. Bad weather prevented experimenting outside.
Experiment 6
Objective: Collect and test hydrogen through electrolysis.
Materials: salt (sodium chloride), water, bowl, aluminum foil, candle, solar panel, test tube, lamp
Process: First, I filled the bowl with water and mixed it with a tablespoon of salt. Next I cut two strips of aluminum foil and folded them in half, leaving the tops open slightly. Placing the ends of the strips in the bowl, I attached the solar panel wires to the ends of the aluminum strips. With the system hooked up, I turned on the lamp. Next I dipped the test tube under the water and slowly drew it out, keeping the opening pointing down into the water so that it remained full. Moving the test tube over to the strips I held it there and caught the gas bubbles. Once the tube was full of gas, I moved it over and held the tube over the lit candle opening downward.
Results: The illuminated solar panel produced gas bubbles of the aluminum strips. Bubbles from the negative strip were hydrogen gas. When the full test tube was held over the flame, it omitted a puff sound.
Observations: The first time I tried to perform this experiment I made a bad mistake. I assembled everything right, but forgot to add the salt. The bubbles that were produced were so small that it would have taken hours to complete. The lack of salt in the water made the connection through the water almost non-existent slowing the process considerably. Once I added the salt the process went much faster and I was able to catch enough gas to perform the test. The positive strip was constantly breaking down and floating across the bowl, causing the process to stop until I replaced it. Once the test tube was filled with hydrogen, moving it over the flame made a distinct puff. This proved that it was hydrogen.
Experiment 7
Objectives: fill and assemble fuel cell
Materials: fuel cell, two small tubes, two big tubes, stoppers, distilled water, syringe
Process: First, I took the two smaller tubes and hooked them into opposite sides of the fuel cell. Next I took the longer tubes and hooked them into opposite sides. Placing one end of the longer tubes in a bowl of distilled water, I taped them in place. Next I hooked the other long tube to the syringe. Pulling back on the syringe, I sucked the distilled water out of the bowl and through the fuel cell. Once all the air had been sucked out of the fuel cell and it was filled with water, I quickly pulled out the syringe and plugged the end of the smaller tube. Plugging the syringe into the other side of the cell, I repeated the procedure and plugged the other small tube.
Results: With all the tubes in place and the cell filled, the cell was ready for testing.
Observations: The process was easy and quick to complete. The only difficulty was with the tubes reaching into the same bowl. Because they were too short I had to get an extra bowl.
Experiment 8
Objectives: Create hydrogen through electrolysis. Test fuel cell.
Materials: already assembled fuel cell, solar panel, distilled water, lamp
Process: First I attached the wires of the solar panel to the fuel cell. Next, I positioned the solar panel so that it got full light from the lamp. Then I turned on the lamp.
Results: The fuel cell produced hydrogen and oxygen out the two long tubes. Bubbles that came out the right side were hydrogen and bubbles coming out the left side were oxygen.
Observations: Because it was already assembled, there were no more problems with the fuel cell. Once the lamp was turned on, the two tubes in the bowls of distilled water produced bubbles. The bubbles on the right side were hydrogen because they were coming out twice as fast as the oxygen was. This can be explained in the scientific name for water H2O.
Experiment 9
Objectives: fill gas tanks and test fuel cell.
Materials: fuel cell car assembly, distilled water, nozzles, gas tanks, syringe
Process: Leaving all the tubes connected to the fuel cell, I pushed the gas tanks into the slot in the back of the car. Next, I unhooked the two longer tubes from the fuel cell and the bowl and pushed a nozzle into one en of each tube. Hooking the tubes back to the fuel cell, I took the other ends and attached them to the fuel tanks. Then I filled the slot that the fuel tanks fit into with distilled water and lifted the tanks slightly so that they filled too. Taking the syringe, I attached it to one of the smaller tubes and pulled the water from the tanks into the fuel cell. After filling both sides of the fuel cell, I moved the lamp over and turned it on.
Results: The fuel produced hydrogen and oxygen filling both the tanks.
Observations: The water level in the slot went up as the tanks filled and forced
the extra water out. The hydrogen tank was twice as big as the oxygen tank,
so they were completely filled at the same time.