Question

What is the composition of aqua regia?

(a) 1:3 of HCl and HNO3

(b) 1:3 of HNO3 and HCl

(c) 1:3 of HCl and H2SO4

(d) 1:3 of H2SO4 and HCl

I got this question in a job interview.

The origin of the question is Electrolytic Cells and Electrolysis in division Electrochemistry of Chemistry – Class 12

Answer 1

Right choice is (b) 1:3 of HNO3 and HCl

Explanation: Aqua regia also known as royal water is a yellow-orange mixture of concentrated nitric acid and hydrochloric acid in the ratio 1:3. It is used by an alchemist to dissolve noble metals like gold and silver.