Multiple choice

Which of the following is used to dissolve noble metals?

  1. Nitric acid

  2. Hydrochloric acid

  3. Sulphuric acid

  4. Aqua regia

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Aqua regia (Latin for 'royal water') is a mixture of nitric acid and hydrochloric acid in 1:3 ratio. It can dissolve gold and platinum, which are 'noble' metals that resist most other acids. The chloride ions form soluble complexes with noble metal ions.