Question

2 mL each of concentrated HCl, HNO₃ and a mixture of concentrated HCl and concentrated HNO₃ in the ratio of 3 : 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be

Options

• Al

• Au

• Cu

• Pt

Answer 1

Au

Explanation - 

A mixture of concentrated HCl and concentrated HNO₃ in the 3 : 1 molar ratio is called aqua regia. It is a yellow-orange fuming liquid that can dissolve gold.