(Courtesy of Kingston Technical Software)
|Red-brown flaky rust||Black magnetite||Blue/green unstable rust|
So, you are wondering, how did we make these experiments.
For the first experiment we put a 5 cm finishing nail brushed with steel wool in a test tube containing 8 mL of tap water. The picture was taken three days later.
The second experiment was carried out with an acidic solution containing 12% acetic acid. You can produce a similar reaction with vinegar which typically contains 3% acetic acid in water. However, you will have to be more patient than we were.
In the third experiment a pellet of sodium hydroxide (caustic 'Drano') was dropped in the test tube of the second experiment. The test tube was capped to prevent air to react with the solution. After three hours the rust precipitates had more or less settled out has you can see in this picture.