The amount of charge in F (Faraday) required to obtain one mole of iron from Fe O is _____ (Nearest — Electrochemistry Chemistry Question

💡 Solution & Explanation

# Solution: Charge Required to Obtain 1 mole of Fe from Fe₃O₄ **Step 1: Identify the reduction reaction** In Fe₃O₄, iron exists in mixed oxidation states: Fe²⁺ and Fe³⁺ (written as FeO·Fe₂O₃). To obtain metallic Fe (0 oxidation state), all iron must be reduced. **Step 2: Determine electrons needed per iron atom** - Fe³⁺ → Fe⁰ requires 3 electrons - Fe²⁺ → Fe⁰ requires 2 electrons - In Fe₃O₄: one Fe²⁺ and two Fe³⁺ ions - Total electrons needed = 1(2) + 2(3) = 8 electrons per Fe₃O₄ **Step 3: Calculate electrons needed for 1 mole of Fe** From Fe₃O₄, we get 3 moles of Fe. - For 3 moles of Fe: 8 electrons needed - For 1 mole of Fe: 8/3 electrons needed ≈ 2.67 electrons **Step 4: Convert electrons to Faraday** Charge in Faraday = electrons needed / Avogadro's number × (1 F per mole of electrons) Alternatively: 8/3 = 2.67 ≈ 3 F (to nearest integer) **Step 5: Round to nearest integer** 2.67 ≈ 3 F Therefore, the answer is **3**.