A à B:         PbCO₃ à PbO + CO₂

On prolonged heating at 470^oC lead(II) oxide (which is also called litharge) partially oxidises to the mixed oxide Pb₃O₄ which contains both lead(II) and lead(IV) ions.

B à C:        6PbO + O₂ à 2 Pb₃O₄

Pb₃O₄ is scarlet and is also known as red lead and as minium. It behaves as PbO₂.2PbO. With nitric acid the basic lead(II) oxide portion reacts to give a solution of lead(II) nitrate, D, and a residue of lead(IV) oxide, E:

C à D + E:    Pb₃O₄ + 4HNO₃ à 2Pb(NO₃)₂ + PbO₂ + 2H₂O.

With lead(II) nitrate solution sodium hydroxide gives an initial precipitate of lead(II) hydroxide F; this substance is amphoteric and reacts with more sodium hydroxide to give a solution of sodium plumbate(II), G, which is colourless:

D à F:        Pb(NO₃)₂ + 2NaOH à Pb(OH)₂ + 2NaNO₃

or, ionically, Pb²⁺ + 2OH^- à Pb(OH)₂.

F à G:        Pb(OH)₂ + 2NaOH à Na₂Pb(OH)₄

Or, ionically, Pb(OH)₂ + 2OH ^- à [Pb(OH)₄]^2-.

Lead(IV) oxide is a strong oxidising agent and oxidises concentrated HCl to chlorine, J, and lead(II) chloride I. Lead(II) chloride complexes with chloride ions to give various species such as PbCl₃^- and PbCl₄^2-, which are yellow and water-soluble:

E à I + J:   PbO₂ + 4HCl à PbCl₂ + 2H₂O + Cl₂.

J à K:         PbCl₂ + Cl^- à PbCl₃^- .

Chlorine oxidises potassium iodide solution to iodine, L, which in the presence of excess iodide ions gives a brown solution of the tri-iodide ion:

J à L: Cl₂ + 2I^- à I₂ + 2Cl^-

             I₂ + I^- à I₃^- .

Lead(II) nitrate solution gives a precipitate of lead(II) iodide M with potassium iodide solution. Lead(II) iodide is bright yellow when solid, but gives a colourless solution in hot water, from which shimmering yellow plates crystallise on cooling. The colour arises from interactions in the crystal lattice and not from the ions themselves, both of which are colourless:

D à M:             Pb²⁺ + 2I^- à PbI₂ .