Question

Hot concentrated sulphuric acid is a moderately strong oxidizing agent. Which of the following reactions does not show oxidizing behaviour? 1) \( Cu +2 H _{2} SO _{4} \rightarrow CuSO _{4}+ SO _{2}+2 H _{2} O \) 2) \( S +2 H _{2} SO _{4} \rightarrow 3 SO _{2}+2 H _{2} O \) 3) \( C +2 H _{2} SO _{4} \rightarrow CO _{2}+2 SO _{2}+2 H _{2} O \) 4) \( CaF _{2}+ H _{2} SO _{4} \rightarrow CaSO _{4}+2 HF \) (NEET-II2016)

Answer 1

Answer: CaF₂+H₂SO₄ →CaSO₄ +2HF

In this reaction, the oxidation number of Ca,H,S and O are not changed (oxidation number not changed means it is not a redox reaction). 

Hence, H₂SO₄ is not acting as an oxidising agent and reducing agent.