SC16

Question 1

What are the components of a simple chemical cell?

Answer 1

2 different metals, each dipped into a solution of one of their salts

a ‘salt bridge’ to allow dissolved ions to pass from one solution to the other

Question 2

Why do batteries go flat?

Answer 2

When one of the reactants is used up, the reaction stops and a voltage is no longer produced

Question 3

Do fuel cells go flat?

Answer 3

 Fuel cells do not go ‘flat’ – they produce a voltage for as long as reactants are supplied

Question 4

What are the advantages of hydrogen-oxygen fuel cell?

Answer 4

1. Much quieter
2. Need less maintenance than a petrol or diesel engine
3. Do not produce carbon dioxide (a greenhouse gas)

Question 5

State the 4 differences between fuel cells and chemical cells. (batteries)

Answer 5

-The voltage (potential difference)
stays the same while the fuel cell
is working

-The voltage (potential difference)
gradually decreases over time
with use

-Have large reserves of fuel so last
a long time

-Have small reserves of chemicals
so need to be recharged or
disposed of

-Cannot be recharged
-Some types are rechargeable but
many are disposable

-Expensive to make
-Cheap to make