Agua regia disolviendo oro

Au + 3HCl + HNO3 → HAuCl4 + NO + 2H2O

Descripción general

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.

Participantes

Rol Sustancia Coeficiente Estado
Reactivo Oro Au 1 (s)
Reactivo Ácido nítrico HNO₃ 1 (aq)
Reactivo Ácido clorhídrico HCl 3 (aq)
Producto Agua H₂O 2 (l)

Ejemplo cotidiano

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.

Importancia industrial

El agua regia se utiliza en la refinación del oro, en química analítica para disolver metales nobles y en la recuperación de metales preciosos de residuos electrónicos.

Preguntas frecuentes

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