Question

The IUPAC name of the complex ion formed when gold dissolves in aqua regia is :

• A. tetrachloroaurate (I)
• B. dichloridoaurate(III)
• C. tetrachloroaurate(III)
• D. tetrachloroaurate(II)

Answer 1

The correct option is C tetrachloroaurate(III)

Aqua-regia is a solution containing conc. $HCl$ and conc. $HN{O}_3$ in the ratio $3:1$. It dissolves noble metals like $Au,Pt,$ etc.

$HN{O}_3+3HCl\to 2H_{2}O+2Cl+NOCl$

$Au+3Cl\to AuC{l}_3$

$AuC{l}_3+HCl\to {AuC{l}_4}^{-}+H^{+}$

The IUPAC name of $\text{Tetrachloroaurate}\left(III\right)$.

Hence, option $C$ is correct.