Question

Classify each of the following reactions as combination, decomposition, displacement or double displacement:
(i) 2Al + Fe₂O₃ → Al₂O₃ + 2Fe
(ii) 2KClO₃ → 2KCl + 3O₂
(iii) BaCl₂+ Na₂SO₄ → BaSO₄ + 2NaCl
(iv) CaO + H₂O → Ca(OH)₂

Answer 1

Explanation:

1 displacement

2 decomposition

3. double displacement

4. combination

Answer 2

Reaction types

Explanation:

(i) 2Al + Fe₂O₃ → Al₂O₃ + 2Fe -- displacement because iron is displaced by aluminium.

(ii) 2KClO₃ → 2KCl + 3O₂ -- decomposition because KClO₃ is decomposed into KCl and oxygen.

(iii) BaCl₂+ Na₂SO₄ → BaSO₄ + 2NaCl --  double displacement because sodium and barium displace each other.

(iv) CaO + H₂O → Ca(OH)₂ -- combination because CaO and water combine to form Ca(OH)₂.