What is Royal water? Mention its uses.

Explanation

When three parts of concentrated hydrochloric acid and one part of concentrated nitric acid are mixed, aquaregia is obtained. This is also known as Royal water. This is used for dissolving gold, platinum etc.
`Au+4H^(+)+NO_(3)^(-)+4Cl^(-) to AuCl_(4)^(-) +NO+2H_(2)O`
`3Pt+16H^(+)+4NO_(3)^(-)+18Cl^(-) to 3PtCl_(3)^(2-) +NO+8H_(2)O`