Chemical cells and fuel cells

Question 1

Describe how to set up a chemical cell. How is a

voltage produced from a chemical cell?

Answer 1

Two metals of different reactivities are placed in an electrolyte.

The more reactive metal releases electrons, becoming positively
charged. The electrons flow to the other electrode which
becomes negatively charged. The difference in the ability of
each electrode to release electrons causes a voltage to be
produced.

Question 2

When will a chemical cell stop producing a voltage?

Answer 2

When one of the reactants has been

used up.

Question 3

What is a fuel cell?

Answer 3

A cell that continually produces a voltage
as long as it is supplied with oxygen and
a fuel (like hydrogen).

Question 4

What is the only product of a hydrogen-oxygen fuel

cell?

Answer 4

Water

Question 5

How does a hydrogen-oxygen fuel cell work?

Answer 5

Hydrogen and oxygen are pumped through
porous electrodes. The electrolyte is often
an acid such as phosphoric acid.

Hydrogen and oxygen react, producing
electricity and water.

Question 6

Write an equation for the overall reaction that takes

place in a hydrogen-oxygen fuel cel

Answer 6

2H2 + O2 → 2H2O

Check google if unsure

Question 7

What are the advantages of using fuel cells?

Answer 7

• No pollution produced.
• Produce more energy than an alternative
  fuel like petrol.
• Continuous process as long as fuel is
  supplied

Question 8

What are the disadvantages of using fuel cells?

Answer 8

• Materials used to make them are expensive.
• High pressure tanks required to store oxygen
  and fuels like hydrogen.
• Hydrogen is expensive and hard to store.
• Efficiency is affected by temperature.