Question

Write the balanced chemical equation for the following reaction. Phases are optional. 

Solid iron(lIl) oxide reacts with hydrogen gas to form solid iron and liquid water

Answer 1

Ans. Given reaction (unbalanced):              FeO + H₂ -------> Fe + H₂O

Balancing redox reactions under neutral condition:

Step 1: Separate the half-reactions. Balance all the elements except O and H in each half-reaction individually.

            Oxidation half reaction:   H₂ -----------> H₂O

            Reduction half reaction: FeO ----------> Fe + ½ O₂

Step 2: Balance O and H to both the half reactions as needed-

            Oxidation half reaction:   H₂ + ½ O₂ -----------> H₂O

            Reduction half reaction: FeO ----------> Fe + ½ O₂

Step 3: Add the two half-reactions to get balanced reaction. Cancel the terms common on opposite side of the reaction-

                        H₂ + ½ O₂ -----------> H₂O

                        FeO ------------------> Fe + ½ O₂

            -------------------------------------------------

FeO(s) + H₂(g) ----> Fe(s) + H₂O(l)

Therefore, balanced reaction is-    FeO(s) + H₂(g) ----> Fe(s) + H₂O(l)