Question

HNO2 can act as oth oxidising and reducing agent

Answer 1

HNO₂ can act as both oxidizing and reducing agent. In HNO₂ oxidation number of nitrogen is +3 so, it can either lose or gain electrons and hence acts as both reducing as well as oxidizing agent.

Examples:

REACTIONS AS OXIDIZING AGENT:

2HNO₂ + 2HI ------------------> 2H₂O + 2NO + I₂
SO₂ + 2HNO₂ ------> H₂SO₄ + 2NO
SnCl₂ + 2HCl + 2HNO₂ --------> SnCl₄ + 2H₂O + 2NO

REACTIONS AS REDUCING AGENT:

HNO₂ + Br₂ + H₂O -----------> HNO₃ + 2HBr
KMnO₄ + 3H₂SO₄ + 5HNO₂ ----------> K₂SO₄ + 2MnSO₄ + 3H₂O + 5HNO₃