C7.6 - Fuel Cells (Finished)

Question 1

What isna fuel cell?

Answer 1

A fuel cell is a cell that is supplied with fuel and oxygen, using energy from reactions between them to produce energy

Question 2

Why are hydrogen-oxygen fuel cells good to use in vehicles?

Answer 2

The only by-products produced by hydrogen fuel cells are oxygen and heat so no pollution

Question 3

Why could furl cells be better than batteries for electric vehicles?

Answer 3

• Batteries are rechargeable but there is a limit how many times they can be recharged
• Batteries are much more polluting to dispose of than fuel cells because of highly toxic metal compounds in them
• Batteries store less energy and charge longer

Question 4

What are some disadvantages of hydrogen fuel cells?

Answer 4

• Hydrogen is highly flammable

- Hydrogen is hard to store

Question 5

When fuel enters a fuel cell it ___ setting up a ___

Answer 5

Becomes oxidised, potential difference within the cell

Question 6

How does a hydrogen-oxygen fuel cell work?

Answer 6

1) The electrolyte is often potassium hydroxide, electrodes often carbon
2) Hydrogen is fed into the anode compartment and oxygen into the cathode
3) At the anode, hydrogen looses electrons to produce H+ ions, that move to the cathode
4) At the cathode oxygen gains electrons and reacts with the H+ to make water
6) The electrons flow through an external electrical circuit

Question 7

Is oxygen or hydrogen reduced in a hydrogen fuel cell? (OILRIG)

Answer 7

Oxygen