Question

fe³⁺ is reduced to fe²⁺ by using

• A. H₂O₂ in the presence of NaOH
• B. Na₂O₂ in water
• C. H₂O₂ in the presence of H₂SO₄
• D. Na₂O₂ in the presence of H₂SO₄

Answer 1

The Correct Option is C, D

The correct answer is/are option/s (C)&(D) : 
H₂O₂ in the presence of H₂SO₄
Na₂O₂ in the presence of H₂SO₄
By using H₂O₂ in the presence of NaOH. In this H₂O₂ will act as a reducing agent and OH ion will act as a base. The balanced reaction is as follows: 
2 Fe³⁺ + 2 H₂O₂ + 2 OH⁻ → 2 Fe²⁺ + 2H₂O + O₂
Another way is by using, Na₂O₂ in water. In the reaction, sodium peroxide will act as a strong oxidizing agent and therefore donate the oxygen atom. Water will provide the medium. The reaction for the same is as follows: 
2Fe³⁺ + Na₂O₂ + 2H₂O → 2 Fe²⁺ + 2NaOH + H₂O₂