Aqua Regia "Royal Water" Kit For Precious Metal Extraction

Aqua regia, the reagent historically called royal water, is the nitric and hydrochloric acid combination used to dissolve gold, platinum, palladium and the other noble metals. This kit supplies the two reagent-grade acids in separate containers, 68–70 percent HNO₃ and 37 percent HCl, for combining in the classic 1:3 volumetric ratio before use.

Freshly prepared, the mixture is yellow to orange from dissolved nitrosyl chloride and chlorine. It is used in precious metal refining and recovery, gold and platinum assay, sample digestion for analytical work, and demonstrations in inorganic and qualitative chemistry teaching.