Fuel cells

Question 1

What is a fuel cell’s job?

Answer 1

• Converts the chemical energy in a reaction between a fuel and oxygen into electrical energy

Question 2

What are the electrodes in a fuel cell made out of?

Answer 2

• Porous carbon (contain main tiny holes)
• Contain a catalyst to speed up the chemical reaction

Question 3

What happens at the anode of a fuel cell?

Answer 3

• Negative electrode
• Hydrogen atoms each lose 1 electron (oxidised)
• Electrons travel around wire to cathode. This sets up a potential difference across the wire
• Hydrogen travels to the cathode through the electrolyte
• H2 + 2H(+) = 2e(-)

Question 4

What happens at the cathode of a fuel cell?

Answer 4

• Positive electrode
• Oxygen reacts with hydrogen and electrons to form water (and heat)
• Oxygen is reduced
• O2 + 4H(+) + 4e(-) = 2H2O

Question 5

Pros and cons of a fuel cell

Answer 5

• Pros = no CO2 emitted, reactants are easy to obtain
• Cons = hydrogen requires energy to produce, explosive when mixed with air, requires lots of space to store