Study of Pb(II) in various H2O-H2SO4 mixtures by differential pulse polarography: solubility of lead sulphate,diffusion coefficient of Pb(II) and half-wave potential of Pb(Hg)/Pb(II)

A study of some properties of Pb(II) in solutions of sulphuric acid was carried out by means of differential pulse polarography. The range of concentrations of acid extended from 0.6 to 70 weight % of H₂SO₄ (0.06-11.5 M). Determination of the solubility of lead sulphate was found to be in good agreement with NBS's results in the range of H₂SO₄ concentrations they studied. With increasing concentration in H₂SO₄, the diffusion coefficient was found to decrease more than expected from the Stokes-Einstein equation, while the standard potential of Pb/Pb(II) related to she was found to increase. This led to a more important self-discharge of the negative electrode of the lead-acid battery.