passwella.
Menu

JAMB Chemistry 1978 Question 42

Question 42

Qualitative Analysis

A solid X when heated gives off a brown gas. If X is soluble in excess sodium hydroxide solution but insoluble in excess ammonium hydroxide solution, then X is

  1. A.basic lead carbonate
  2. B.lead (II) nitrate
  3. C.sodium carbonate
  4. D.zinc nitrate
  5. E.sodium nitrate
Show the answer and explanation

Answer: B (lead (II) nitrate)

Explanation

The brown gas (NO2) shows a nitrate of a heavy metal. Lead hydroxide dissolves in excess NaOH but not in excess ammonia; zinc hydroxide would dissolve in both.