JAMB Chemistry 1983 Question 16

Question 16

Redox Reactions

In which of the following processes is iron being oxidized?
1. Fe + H₂SO₄ → FeSO₄ + H₂
2. FeSO₄ + H₂S → FeS + H₂SO₄
3. 2FeCl₂ + Cl₂ → 2FeCl₃
4. 2FeCl₃ + SnCl₂ → 2FeCl₂ + SnCl₄.

A.1 only
B.2 only
C.3 only
D.1 and 3
E.2 and 4

Show the answer and explanation

Answer: D (1 and 3)

Explanation

Iron's oxidation number rises from 0 to +2 in 1 and from +2 to +3 in 3. It stays +2 in 2 and falls from +3 to +2 in 4.