Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
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perchloric acid : HClO4
sodium hydroxide : NaOH
lead nitrate : Pb(NO3)2
Class:
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elem=Pb
precipitation
Summary:
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Lead(II) hydroxide is easily converted to lead(II) oxide by simple boiling. The
lead(II) oxide appears as nice glittering gold/yellow crystals.
Description:
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Prepare a solution of lead(II) nitrate and a solution of sodium hydroxide in
two separate test tubes and add these solutions to each other, such that the
amount of lead nitrate is approximately the same as the amount of sodium
hydroxide: When the two colorless solutions come in contact with each other,
then a white finely divided precipitate is formed. This precipitate is fairly
compact and is not slimy.
Heat the test tube with the white precipitate until the liquid starts boiling:
While the liquid heats up, more and more of the white precipitate dissolves
until the liquid is (nearly) clear. When the liquid becomes so hot that it is
nearly boiling, then glittering yellow/gold crystals appear. When heating is
continued, then a lot of glittering crystals are produced and these quickly
settle at the bottom and part of them also stick to the glass. These crystals
settle very fast, it is just a matter of second
Rinse the yellow/gold crystals a few times with distilled water by decanting
the water and adding new water a few times. Then add a small quantity of
perchloric acid (50% by weight): The crystal mass quickly dissolves and a
colorless solution is obtained.