Question

How many moles of electrons are required to reduce 0.5 moles of Fe\(^{3+}\) to Fe\(^{2+}\)?

• A. 1 mole
• B. 0.5 mole
• C. 1.5 moles
• D. 2 moles

Hint:

Always balance redox equations to find electron transfer. Here, each Fe\(^{3+}\) gains 1 electron to become Fe\(^{2+}\).

Answer 1

The Correct Option is B

Step 1: Understand the reduction reaction.
Fe\(^{3+}\) is reduced to Fe\(^{2+}\) by gaining one electron: \[ \text{Fe}^{3+} + e^- \rightarrow \text{Fe}^{2+} \] Step 2: Use mole ratio.
1 mole of Fe\(^{3+}\) requires 1 mole of electrons.
Therefore, 0.5 moles of Fe\(^{3+}\) requires:
\[ 0.5 \times 1 = 0.5 \text{ moles of electrons} \]