West Lothian Council
Lorna C. Webster
1
Electricity from chemistry
Read
Our main supply of electricity comes from power stations
where coal, oil or natural gas is burned to produce heat that
turns water to steam
that turns a turbine to
make electrical energy.
So power stations use
chemical reactions
(burning) to make
electricity.
We also get a supply of electricity from batteries.
It is highly likely that you have used
batteries at some point so far in your life
to supply electricity to appliances.
Batteries contain chemicals and these
chemicals react to make electrical energy.
So, in a battery, electricity comes from chemical reactions.
You will also know that batteries don't last forever. They go
flat when the chemicals inside have been used up.
There are many different types of batteries. They have
different sizes and shapes for different uses.
Write a heading and do the work below.
1. Why can we say that the electricity from power stations
comes from chemical reactions?
2. What do batteries contain inside them?
Lorna C. Webster
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3. Where does the electricity come from when a battery is
used?
4. Explain why batteries will eventually go flat.
5. Collect the information sheet called "batteries" and answer
the following questions.
a) List some uses for the zinc-carbon type battery.
b) Write down one advantage and one disadvantage for the
silver oxide battery?
c) What is a lithium-dioxide battery used for?
d) List three advantages for the zinc-air battery.
e) What is the main advantage with a Nickel- Cadmium
battery?
Lorna C. Webster
3
Rechargeable batteries
Read
You should already know that most batteries will go flat when
the chemicals are used up but one of the batteries on the
information sheet can be recharged if it has gone flat. You are
now going to do an experiment to find out about another type of
rechargeable battery called a lead-acid battery.
Before you start write a heading. Answer the questions in your
jotter as you work through the experiment.
Collect
a beaker
a bottle of sulphuric acid
2 lead plates
2 wires
a bulb
Set up the experiment as shown in the diagram below.
bulb
leads
lead
plates
sulphuric
acid
1. Does the bulb light?
Lorna C. Webster
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Now disconnect the bulb,
collect a power pack and
connect the leads to the
red and black points on
the power pack. Make
sure the pack is set to
2V before you switch it
on.
Switch the power on for
about 5 minutes.
power pack
2V
DC
leads
lead
plates
sulphuric acid
2. Do you see anything that tells you if a chemical reaction has
happened? Explain your answer?
bulb
Now switch off the
power pack, disconnect
it and put the bulb back
into the circuit.
leads
lead
plates
sulphuric
acid
3. Does the bulb light?
4. What eventually happens to the bulb?
5. Why do you think this happens to the bulb?
6. What would you do if you wanted to light the bulb again?
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7. Copy and complete the sentences below.
When the c__________ inside a battery are used up,
the battery will not produce electricity and goes
f_____. Some batteries are rechargeable. Examples of
rechargeable batteries are the nickel-cadmium battery
and the l_____-a______ battery.
8. Do you think there might be any problems with safety when
lead-acid batteries are used? Explain your answer.
Lorna C. Webster
6
More about making electricity
Read
You should know from first year that to make an electric
current flow you need a complete circuit. In
the next experiment you will find out how to
make a complete circuit and produce electricity
using only a salt solution and two different
metals connected by wires.
Write a heading and do the work below.
1. Draw a diagram of the following experiment.
2. Collect the equipment you need and set up experiment. Write
down the reading you see on the voltmeter.
voltmeter
V
leads
magnesium
zinc
salt solution
3. Now pour out the salt solution and repeat the experiment
with a dry beaker. Is there any electricity produced when
there is no salt solution?
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4. Copy and complete the sentences below.
To generate electricity in a circuit is simple. All we need
to do is to connect two different metals together and
separate them with a salt solution. This type of
experiment is called a cell. A cell is an arrangement of
apparatus and chemicals that uses chemical reactions
to produce an electric current. If the salt solution is
missing, there is a __________ in the circuit so no
electricity can flow.
Your teacher may show you how to make a fruit or coca cola
battery.
Lorna C. Webster
8
Making more electricity
The size of the voltage that is produced in a circuit depends on
the metals that are used in the circuit.
Sarah set up the following experiment to find out about how
much voltage can be produced using different metals. The
results are shown in the table.
voltmeter
V
metal X
metal Y
salt solution
metal X
copper
copper
copper
metal Y
lead
zinc
magnesium
voltage(volts)
0.3
1.1
1.9
Write a heading and do the work below.
1. Copy the diagram of Sarah's experiment and her table of
results.
2. Copy and complete the sentence below by choosing the
correct answer.
When different metals are used in a cell the voltage
that is produced stays the same/ changes.
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3. Look up the reactivity series in a data book.
a) How far apart are copper and lead in the series?
b) How far apart are copper and zinc in the series?
c) How far apart are copper and magnesium in the series?
d) Now look at the voltages for each experiment and copy the
sentence below by choosing the correct answer:
The further apart the metals are in the reactivity series the
higher/lower the electrical voltage that can be produced.
Your teacher may ask you to:
 Design a poster about what makes iron rust or how to stop
iron rusting.
 Do experiment 2.25 about making batteries.
 Try SATIS units 103, 706, or 604
Lorna C. Webster
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