Finally, the solution is treated with concentrated sulfuric acid H2SO4, to separate out lead tetrachloride.

[3] Also, because of the presence of empty d orbitals on the Pb atom, oxygen can bind to it before a Pb–Cl bond has to break, thus requiring less energy.

[3] Thus while carbon tetrachloride is a stable compound, with lead the oxidation state +2 is favored and PbCl4 quickly becomes PbCl2.

Indeed, the inert pair effect causes lead to favor its +2 oxidation state: Pb atom loses all its outermost p electrons and ends up with a stable, filled s subshell.

[8] Lead can be absorbed by the body through several routes, primarily inhalation but also ingestion and dermal contact.