2 mL each of concentrated HCl, HNO 3 and a mixture of concentrated HCl and concentrated HNO 3   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

(A) Al

(B) Au

(C) Cu

(D) Pt



3:1 solution of HCl and HNO 3 is called Aqua regia and it is able to dissolve gold.


So, the correct option is (b) Au

  1. Class 10
  2. Chapter 3 Class 10 - Metals and Non-Metals (Term 1)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo