Question

Aqua regia consists of:
A. hydrochloric acid
B. carbonic acid
C. nitric acid
D. both A and C

Answer 1

Hint: Aqua regia has yellow orange or red colour. It is a fuming liquid. Concentrations of all the constituents are high. This is a compulsory condition for the solution to be called Aqua Regia.

Complete answer:
Aqua regia consists of a mixture of hydrochloric acid and nitric acid. The ratio of hydrochloric acid and nitric acid is 3:1. This is the volume ratio. Thus, when you mix one litre of hydrochloric acid with three litres of nitric acid, you form aqua regia.
Alchemist gave the name ‘aqua regia; which means ‘royal water’ as noble metals such as gold and platinum are soluble in aqua regia.
These noble metals, gold and platinum are insoluble in either pure nitric acid or pure hydrochloric acid.
In an analytical laboratory, you can use aqua regia to dissolve a few iron ores, rock phosphates, alloys of chromium and nickel, certain slags, selenium and antimony metals, sulphides of arsenic and mercury.
The reaction between nitric acid and hydrochloric acid in aqua regia releases nascent chlorine.
\[{\text{HN}}{{\text{O}}_3} + {\text{HCl}} \to {\text{NOCl + 2}}{{\text{H}}_2}{\text{O + 2}}\left[ {{\text{Cl}}} \right]\]

Hence, the correct option is the option D both A and C.

Note:
Aqua regia cannot dissolve all the metals.
To manufacture chloroauric acid, you will need aqua regia.
In the Wohlwill process, you can use aqua regia as an electrolyte to refine gold to the highest purity (99.999%).