Question

Aqua regia is prepared by mixing concentrated $\mathrm{HCl}$and concentrated ${\mathrm{HNO}}_3$in the ratio:

• A. 1:3
• B. 1:4
• C. 3:1
• D. 3:2

Answer 1

The correct option is C

3:1

The explanation for the correct option:

(C) Aqua regia: It is a yellow-orange or red-colored fuming liquid.

• Aqua regia is a mixture of concentrated Hydrochloric acid, $\left(\mathrm{HCl}\right)$ and Nitric acid, $\left({\mathrm{HNO}}_3\right)$ in a ratio of 3:1.

Uses of Aqua regia:

• It can dissolve noble metals such as Gold $\left(\mathrm{Au}\right)$and Platinum$\left(\mathrm{Pt}\right)$.
• Aqua regia is mainly used for the manufacture of Chloroauric acid $\left({\mathrm{HAuCl}}_4\right)$
• It is used as an electrolyte in the Wohlwill process to refine gold to the purity of 99.999%.

Hence, option (C) is correct.