Page 29 - Fuel Cell Teacher Edition
P. 29
Pre Lab
Que s tions
S ol utions
1. What type of energy is converted into electrical 7. What is the difference between a PEM fuel cell
energy in a fuel cell? and an alkaline fuel cell?
Chemical energy is converted into PEM fuel cells use a semi-permeable membrane
electrical energy. to allow ions to flow but block electrons. Alkaline
fuel cells allow anything in the electrolyte to flow
2. What was William Grove trying to prove in 1843 freely between the electrodes.
when he built the first fuel cell?
8. How does the efficiency of most fuel cells
He was trying to prove that electrolysis compare to Nuclear Power?
could be reversed. Instead of using electricity
to separate water into hydrogen and oxygen, Most fuel cells max out at 60% efficiency, which
he would use hydrogen and oxygen to create is much less than the potential efficiency of
water. nuclear power.
9. Why do you think we send fuel cells into
3. The lack of what substance(s) would make Mr. space instead of nuclear reactors on manned
Grove’s fuel cell stop working?
missions?
If the hydrogen and oxygen levels were Nuclear reactors are more dangerous if
sufficiently low the cell would cease to something goes wrong. They are more complex,
function. and therefore more likely to fail.
4. What are the three major components of a fuel 10. Why aren’t Magnesium-Air Fuel Cells in common
cell? use if their efficiency is so high?
❖ Anode ❖ Cathode ❖ Electrolyte The plates have to be cleaned regularly and the
expensive magnesium cannot be reclaimed. The
5. What do we call a collection of fuel cells electrolyte becomes contaminated over time.
connected together electrically?
A stack 11. What is the difference between the following two
symbols in a chemical equation?
6. Why do PEM fuel cells require a supply of gas? denotes a reversible reaction, which will find
The gas allows the reaction to take place by an equilibrium with reactants and products.
providing molecules that become ions by denotes an irreversible reaction, which will
liberating electrons. have only products once complete.
12 TOTAL REDOX™ – FUEL CELLS TOTAL REDOX™ – FUEL CELLS 13
