C6.2.10 - Producing electricity using chemistry

Question 1

What are chemical cells?.

Answer 1

Devices that produce a potential different from chemical reactions

Question 2

What is a potential difference?

Answer 2

The difference in voltage between 2 specific points

Question 3

What is a fuel cell?

Answer 3

A device that produces electricity by the reaction of a fuel with oxygen, without combustion

Question 4

What is the equation for when hydrogen molecules lose electrons and become hydrogen ions?

Answer 4

2H2(g) -> 4H+(aq) + 4e-

Question 5

What is the equation for when hydrogen ions combine with oxygen and electrons at the other side to form water vapour?

Answer 5

4H+(aq) + O2(g) + 4e- -> 2H2O(g)

Question 6

Name the waste product of a hydrogen-oxygen fuel cell?

Answer 6

Water (vapour)

Question 7

Explain, in terms of electrons, whether the reactions at each side of a hydrogen-oxygen fuel cell are oxidation or reduction reactions

Answer 7

The reaction at the hydrogen side/fuel side/anode is oxidation, because hydrogen loses electrons
The reaction at the oxygen side/cathode is reduction, because hydrogen ions gain electrons

Question 8

What type of reaction takes place in a chemical cell?

Answer 8

Exothermic reaction