• Place the following in the Petri dish:

-  1 drop of potassium bromide solution (~ 0.5 – 2 M);

-  1 drop of potassium iodide solution (~ 0.1 – 0.5 M);

-   a piece of damp blue litmus paper

-   drops of 0.5 M copper(II) chloride solution until the ‘merged’ drop just touches both electrodes.

• Place the lid on the Petri dish and then connect the electrodes to a DC source (9 volts).
• Switch on and observe what happens: (i) at the electrodes, (ii) to test the electrodes, (iii) to the moist litmus paper.

Wear eye protection.

Seal the glass Pasteur pipette by heating the end (tip) in a burner flame. Allow to cool.

Prepare a long-tip plastic pipette to add some liquid paraffin down the sealed pipette (~ 0.5 cm³).

Insert some mineral wool into the pipette so that the liquid paraffin is all absorbed by the wool.

Use a drinking straw as a micro-scale spatula to place some aluminium oxide powder into the sealed Pasteur pipette.

Set up the sealed pipette as shown in the diagram.

Support/hold the sealed Pasteur pipette (at its wide end, around the silicone tubing) with a clamp.

Place a small test tube containing bromine water* in position (see diagram) so that the bubbling gas can pass through it. 

* Acidified 0.002 M potassium manganate(VII) solution can be used in place of bromine water. The colour change is more noticeable.Place the burner so that the flame is at the junction of the mineral wool and aluminium oxide.

Light the spirit burner.

Once it is bubbling through quickly, the gas could be lit as it emerges from the pipette.