Colloidal Plumbic Acid

Colloidal Plumbic Acid is obtained by the dialysis of potassium plumbate solution, which is completely hydrolysed at ordinary atmospheric temperature into PbO₂.Aq + 2KOH. The hydrosol finally obtained, which contains PbO₂ and K₂O in the ratio 98.13:1.87, may be filtered, boiled, evaporated to a syrup, and again dissolved in water. The small amount of potash present - the " Solbildner " - is of the same order as the amounts of hydrochloric acid necessary for the existence of the hydrosols of aluminium, chromic and ferric hydroxides.