passwella.
Menu

JAMB Chemistry 1978 Question 15

Question 15

Metals and their Compounds

When each of the nitrates of potassium magnesium and iron is heated,

  1. A.all the nitrates decompose to their oxides
  2. B.the nitrate of magnesium gives the nitrite and oxygen
  3. C.the nitrates of magnesium and iron give the oxides
  4. D.the nitrate of iron gives the nitrite and oxygen
  5. E.the nitrate of the magnesium is not decomposed.
Show the answer and explanation

Answer: C (the nitrates of magnesium and iron give the oxides)

Explanation

Potassium nitrate (very reactive metal) gives the nitrite and oxygen, but nitrates of less reactive metals such as magnesium and iron decompose to the oxide, nitrogen(IV) oxide and oxygen.