(i) What is aqua-regia?
(ii) State the use of aqua-regia.
(iii) What is the function of HCl in preparation of aqua-regia?
(i) What is aqua-regia?
(ii) State the use of aqua-regia.
(iii) What is the function of HCl in preparation of aqua-regia?
(i) Aqua – regia is a mixture of three parts of concentrated hydrochloric acid and one part of concentrated nitric acid.
(ii) Aqua – regia is used to dissolve noble metals like gold and platinum, and form the respective chlorides.
(iii) Hydrochloric acid provides chloride ions, which react with nitric acid to form nascent chlorine. Nascent chlorine reacts with gold and platinum to form the respective chlorides.
HNO3 + 3HCl → NOCl + 2H2O + 2[Cl]
Nascent
chlorine
Au + 3[Cl] → AuCl3
Pt + 4[Cl] → PtCl4
(i) Aqua – regia is a mixture of three parts of concentrated hydrochloric acid and one part of concentrated nitric acid.
(ii) Aqua – regia is used to dissolve noble metals like gold and platinum, and form the respective chlorides.
(iii) Hydrochloric acid provides chloride ions, which react with nitric acid to form nascent chlorine. Nascent chlorine reacts with gold and platinum to form the respective chlorides.
HNO3 + 3HCl → NOCl + 2H2O + 2[Cl]
Nascent
chlorine
Au + 3[Cl] → AuCl3
Pt + 4[Cl] → PtCl4
