Aqua Regia Dissolving Gold

Au + 3HCl + HNO3 → HAuCl4 + NO + 2H2O

Tổng quan

Aqua regia (3:1 mixture of HCl and HNO₃) dissolves gold, which is inert to either acid alone. Nitric acid oxidizes gold to Au³⁺ while hydrochloric acid provides chloride ions that stabilize the gold as [AuCl₄]⁻ complex. The synergy between the two acids makes aqua regia effective against noble metals.

Người tham gia

Vai trò Chất Hệ số Trạng thái
Chất phản ứng Gold Au 1 (s)
Chất phản ứng Nitric Acid HNO₃ 1 (aq)
Chất phản ứng Hydrochloric Acid HCl 3 (aq)
Sản phẩm Water H₂O 2 (l)

Ví dụ thực tế

During WWII, George de Hevesy dissolved the Nobel Prize gold medals of Max von Laue and James Franck in aqua regia to hide them from the Nazis.

Tầm quan trọng công nghiệp

Aqua regia is used in gold refining, analytical chemistry for dissolving noble metals, and in recovering precious metals from electronic waste.

Tính chất

Loại
Redox
Thuận nghịch
Không
Năng lượng
Tỏa nhiệt
ΔH
-150,0 kJ/mol

Phản ứng liên quan

Iron(II) to Iron(III) Oxidation by Oxygen Bleaching with Sodium Hypochlorite Copper Reduction of Silver Ion Cerium(IV) Reduction by Iron(II) Chlorine Oxidation of Bromide Copper Oxidation by Nitric Acid Hypochlorite Oxidation of Hydrogen Peroxide Hydrogen Peroxide as Oxidizing Agent (Acidic) Zinc Reduction of Silver Ion Displacement of Hydrogen from Acid by Magnesium

Frequently Asked Questions

What is the equation for Aqua Regia Dissolving Gold?
The balanced equation is: Au + 3HCl + HNO₃ → HAuCl₄ + NO + 2H₂O.
What type of reaction is Aqua Regia Dissolving Gold?
Aqua Regia Dissolving Gold is a redox reaction.
Is Aqua Regia Dissolving Gold exothermic or endothermic?
Aqua Regia Dissolving Gold is exothermic (releases energy). The enthalpy change (ΔH) is -150.0 kJ/mol.