Hexahydroxyplumbic Acid, H₂[Pb(OH)₆]

When dilute acetic acid is added to a solution of potassium plumbate cooled with ice, a flocculent precipitate separates which is lighter in colour even than ferric hydroxide. It gradually turns brown, however, and when dried in the air produces lead dioxide. This precipitate may be H₂[Pb(OH)₆], because potassium plumbate, from which it is derived, is believed to be K₂[Pb(OH)₆].