Page 40 - Fuel Cell Teacher Edition
P. 40
PO S T Lab
Que s tions
S ol utions
1. When did the fuel cell start to produce electricity? 4. Why do you think the reaction started without
The fuel cell will begin producing electricity as any input energy, even though hydroxide needs
soon as the cathode, anode, and electrolyte to be free to interact with the zinc plate?
are in place. More precisely, the zinc anode When sodium hydroxide is in solution the
readily releases electrons when it touches the sodium and hydroxyl groups become ions and
electrolyte, and the cathode readily accepts are dissociated. This is why the water releases
electrons when it touches the electrolyte. These heat when sodium hydroxide is added to it.
two concurrently will create useful electrical In effect the energy to start the reaction was
current. applied when making the sodium hydroxide
compound.
2. Which fuel cell electrode was positive? Which
was negative? 5. What could you do to make the fuel cell more
The zinc anode is negatively charged because efficient?
it frees an electron which flows to the cathode. Students answers will vary depending on the
The air cathode is positively charged. cell they created. Increased surface area of
the electrodes or an increased concentration
3. Why did the electricity go through the wire of electrolyte will improve fuel cell output, and
instead of the electrolyte between the increased surface area can be achieved numerous
electrodes? ways. Increasing the copper wire length for the
The electrolyte is less conductive than the wire cathode or using a thicker wire gauge will reduce
connecting the two electrodes. the resistance between carbon and the wire.
24 TOTAL REDOX™ – FUEL CELLS TOTAL REDOX™ – FUEL CELLS 25
