Question

Noble metals can only be dissolved in

• A. Conc. HNO₃
• B. Conc. HCl
• C. Conc.H₂SO₄
• D. Aqua-regia

Answer 1

The correct option is D

Aqua-regia

Noble metals cannot be dissolved by common strong acids like ${\text{HNO}}_3,\text{HCl},{\text{H}}_2{\text{SO}}_4$ alone, but they are dissolved in aqua regia. It is a highly corrosive mixture of 2 strong acids in a fixed ratio, 1 part ${\text{HNO}}_3$ + 3 parts $\text{HCl}$.