2 mL each of conc. HCl, `HNO_(3)` and a mixture of conc. HCl and conc. `HNO_(3)` in the ratio of3 : 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. The metal could be A. AlB. AuC. CuD. Pt

2 mL each of conc. HCl, `HNO_(3)` and a mixture of conc. HCl and conc.

1.	2 mL each of conc. HCl, `HNO_(3)` and a mixture of conc. HCl and conc. `HNO_(3)` in the ratio of3 : 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. The metal could be A. AlB. AuC. CuD. Pt
Answer» Correct Answer - b,d A mixture of cone. HOl and cone. `HNO_(3)` in the ratio of 3 : 1 is known as aqua-regia. Gold (AU) and platinum (Pt) dissolve only in aqua-regia.

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