5.2 Chemical cells and fuel cells

Question 1

What is voltage produced by cell dependent on?

Answer 1

Type of electrode
Electrolyte

Cells contain chemicals which react to produce electricity

Question 2

What is a battery?

Answer 2

Two or more cells connected in series to provide a greater voltage

Question 3

What are the properties of non-rechargeable cells & batteries?

Answer 3

Chemical reactions stop when one of the reactants has been used up

Alkaline batteries are non-rechargeable

Question 4

What are the properties of rechargeable cells & batteries?

Answer 4

Can be recharged because the chemical reaction is reversible

Electrical current supplied to reverse the reaction

Question 5

What are the properties of fuel cells?

Answer 5

Supplied by external source of fuel e.g. petrol and oxygen or air

Fuel oxidised electrochemically to produce a potential difference

Question 6

Fill out the differences between a hydrogen fuel cell and rechargeable cells

Answer 6

Question 7

What is the half equation at the anode in a hydrogen fuel cell?

Answer 7

H2(g) → 2e– + 2H+(aq)

Question 8

What is the half equation at the cathode in a hydrogen fuel cell?

Answer 8

4H+(aq) + O2(g) + 4e– → 2H2
O(g)