Today I found some old lead. I tried lots of ways of chemically removing the dull oxide layer to reveal the shiny metal itself. But it did not work. I
tried:
.Boiling in NaHSO4 solution
.Boiling in NaOH solution (concentrated)
.Boiling in dilute nitric acid (obviously because the nitric acid was oxidizing, it could not work)
Finally I gave up, and just melted it and poured it out.
But melting leaves a lot of residues (lead+oxides of lead on the inside of the (metal) container. Is there a way to remove the oxide layer chemically?
From the searches on the internet, it appears that HCl and cold alkali metal hydroxide solutions will, over time. But I want to confirm this+see if
there is any other quicker ways.
Also, I haven't got mineral oil or de oxygenated water right now. Would storing the shiny lead in a NaCl solution (displaces oxygen out of water) be
able to prevent it from going dull again? watson.fawkes - 20-3-2012 at 08:13
Is there a way to remove the oxide layer chemically?
Acetic acid. See the two lead acetate pages on Wikipedia. I haven't tried it personally, as I don't want to deal with soluble Pb.arsphenamine - 20-3-2012 at 13:38
Lead salts may be precipitated as PbSO<sub>4</sub> with sulfuric acid.
Ksp is around 10<sup>-8</sup>.