Question 48
Qualitative AnalysisA piece of metal (M) is dissolved in nitric acid and the resulting solution is treated with a small quantity of sodium hydroxide to produce a white precipitate (B) which redissolves on the addition of excess alkali. The precipitate (B) when ignited in a crucible produces the oxide of the metal (M). The metal M is
- A.Zn
- B.Cu
- C.Al
- D.Au
- E.Ca
Show the answer and explanation
Answer: A (Zn)
Explanation
Zinc dissolves in nitric acid, and its white hydroxide dissolves in excess NaOH (it is amphoteric). Copper gives a blue precipitate and calcium's does not redissolve; aluminium is made passive by nitric acid.