5 mL each of concentrated HCl, `HNO_(3)` and a mixture of concentrated `HNO_(3)` (5 mL) 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. The metal could be

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

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

2 mL each of conc. HCl, conc. HNO3 and a mixture of conc.HCl and 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. the metal could be

5ml water is taken in 3 test tubes. Copper, sodium and magnesium of equal mass are dropped in different test tubes. Test tubes having copper and magnesium are heated: Write the observations in the heated test tubes.

Four test tubes were taken and marked A, B, C and D respectively. 2 mL of solution of Al_(2)(SO)_(3) in water was filled in each of the four test-tubes. Clean piece of metal zinc was placed in test tube A, clean iron nail was put in test tube B, clean copper wire was placed in test tube C and a clean aluminium wire was placed in test tube D. What colour change would you observe in all the four tubes ?