Aqua regia - Definition
FRDefinition
Aqua regia is obtained by mixing one volume of nitric acid with two to four volumes of hydrochloric acid. It is recognizable by its yellowish color. Aqua regia is able to dissolve gold, platinum, and tantalum, noble metals that cannot be dissolved in other acids. The treatment of tantalum with aqua regia enables it to be used in the medical field, especially in the creation of dental implants and pacemakers.