Aqua regia is a mixture of hydrochloric acid (HCl) and nitric acid at a ratio of either 3: 1 or 4: 1 . It is a reddish-orange or yellowish-orange fuming liquid. The term is a Latin phrase, meaning "king's water". The name reflects the ability of aqua regia to dissolve the noble metals gold, platinum, and palladium. Aqua regia is useful to dissolve gold and platinum and finds application in the extraction and purification of these metals. Chloroauric acid may be made by using aqua regia to produce electrolytes for the Wohlwill process. This process refines gold to extremely high purity A similar process is used to produce highpurity platinum.