Gold parting will not dissolve gold, nearly pure gold (very close to 99.5% pure) will be left behind after the reaction is complete. After removing the solid gold other elements like silver and copper may be extracted from the liquid. To get the gold to a very high level of purity (999 fine gold) it is sometimes processed further with aqua regia to effectively remove all the impurities. Aqua regia was also used for parting. It was made by adding sal ammoniac to nitric acid which produced a mixture of hydrochloric acid and nitric acid. This acid dissolved the gold to a
Acid–base reaction these examples. For instance, carbon monoxide acts as a Lewis base when it forms an adduct with boron trifluoride, of formula FB←CO. Adducts involving metal ions are referred to as co-ordination compounds; each ligand donates a pair of electrons to the metal ion. The reaction can be seen as an acid–base reaction in which a stronger base (ammonia) replaces a weaker one (water) The Lewis and Brønsted–Lowry definitions are consistent with each other since the reaction is an acid–base reaction in both theories. One of the limitations of the Arrhenius definition is its reliance on water solutions. Edward Curtis Franklin