The solubility of Lead in ...
Published by Stewart Shipard, Owner Manager at SLS Technology Pty Ltd - a Water Industry company
The solubility of Lead in water is very much misunderstood. Many basic chemistry texts state that Lead chloride is insoluble but in reality the solubility of PbCl2 is many time greater than the recommended potable water levels. In hypersaline water PbCl2 is highly soluble, this is because lead forms soluble complex anions. Without this capability your car would not run as Pb is soluble in your car battery even though PbSO4 has an order of magnitude lower solubility the PbCl2.
Organic compounds such as acetate, and carboxylates from polymers etc provide even stronger formation coefficient for complex lead anions.
Lead is soluble in potable water is because the ratio of the complex forming anions to lead usually found in potable water is ideal for solubilising small amounts of Lead and it is common practise in water treatment plants to apply additives that enhance the formation of soluble lead complex anions.