Question

Aqua-regia is a mixture of hydrochloric acid and sulphuric acid.
(A) True
(B) False

Answer 1

Hint: The mixture of nitric acid and hydrochloric acid gives a product that can dissolve gold. This product is used in cleaning gold ornaments. It is also used in cleaning glassware in labs.

Complete step by step solution:
- Aqua-regia was discovered by Jabir Bin Hayyan around the year 800AD.
- Aqua- regia is actually a corrosive acid mixture of nitric acid ($HN{{O}_{3}}$) and hydrochloric acid (HCl) in the molar ratio of 1:3.
- Aqua-regia is also known by the name- royal water. It is a yellow-orange coloured fuming liquid.
- Aqua-regia can be represented as-

- When the acids are mixed in the 3:1 ratio, the following reactions occur-

\[\begin{align}
  & HN{{O}_{3}}(aq)+3HCl(aq)\to NOCl(g)+C{{l}_{2}}(g)+{{H}_{2}}O \\
 & 2NOCl(g)\to 2NO(g)+C{{l}_{2}}(g) \\
 & 2NO(g)+{{O}_{2}}(g)\to 2N{{O}_{2}}(g) \\
\end{align}\]
- Therefore, the answer is option (B) false. This is because aqua-regia is not a mixture of hydrochloric acid and sulphuric acid, but a mixture of hydrochloric acid and nitric acid.

Additional Information:
- Aqua-regia has a wide range of uses in both laboratories and industries.
- It is used in laboratories to clean glassware that was used for reactions containing organic compounds and metals.
- Aqua-regia is extremely explosive and has been the cause of several explosives due to mishandling.

Note: Aqua-regia is obtained only when we mix nitric acid and hydrochloric acid in the molar ratio of 1:3. Any other ratio of these acids might have similar properties, but they are not called aqua-regia.