Elvevoll Oppvekstsenter, Norway
Ecole Privée Saint Melaine, France
Zer Comte Arnau, Spain
Carnalbanagh Primary School, Northern Ireland
Podruznicna osnovna sola Razbor, Slovenia
COMENIUS 2004/2005
School development project :
« Small schools – big opportunities »
Title: Finding the composition of water
Aims:
Resources:
- to learn that water is a
compound from two different
elements – gases: oxygen and
hydrogen.
- glass trough,
- aluminium foil,
- flat wooden strip,
- two test tubes,
- rubber bands,
WATER – LEVEL 3
- insulated copper wires,
- sodium bicarbonate,
- nine volt battery.
Method:
1. Pour some water into the glass trough (2/3 recommended).
2. Pure water is a not a very good conductor of electricity, add some sodium bicarbonate to improve the
conductivity.
3. Attach the two test tubes to the flat wooden strip using the rubber bands. Fill these test tubes with prepared
solution and invert them into the trough.
4. Cut the copper wire into two pieces, remove the insulation from the edges of the copper wire.
5. Attach the aluminium strips to one edge of both the wire pieces and insert an aluminium strip into each of the test
tubes. These strips act as the electrodes.
6. Attach the other ends of the copper wires to the positive and negative terminals of the battery.
7. Now the circuit is complete.
Expected outcomes:
As current passes through the water you will see bubbles arising from near the electrodes and
rising to the top of the tubes. You will also notice that the water level in the test tubes goes down
unequally. The tube with the lower water level contains hydrogen while the other tube contains
oxygen.
Suggested questions:
Are the levels of water in both tubes equal?
What are the names of gases inside the tubes?
Why are these gases important in our life?
Booklet of science experiments for mixed age groups / ISBN 961-91615-0-5