The composition of a sample of Wustite is `Fe_(0.93)O_(1.00)`. What fraction of the iron is present in the form of `Fe (III)`?

Options

A. 0.1505
B. 0.25
C. 0.35
D. 0.45

Answer

To solve the problem of determining the fraction of iron present in the form of Fe(III) in the compound Wustite (Fe₀.₉₃O₁.₀₀), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Composition**:
- The given composition of Wustite is Fe₀.₉₃O₁.₀₀. This means there are 0.93 moles of iron (Fe) and 1 mole of oxygen (O) in the compound.

2. **Defining Variables**:
- Let \( x \) be the number of moles of Fe in the +3 oxidation state (Fe³⁺).
- Consequently, the remaining iron will be in the +2 oxidation state (Fe²⁺), which can be expressed as \( 0.93 - x \).

3. **Charge Balance**:
- The total positive charge from the iron ions must balance the negative charge from the oxygen ions to maintain electrical neutrality.
- The charge contribution from Fe³⁺ is \( 3x \) (since each Fe³⁺ contributes +3 charge).
- The charge contribution from Fe²⁺ is \( 2(0.93 - x) \) (since each Fe²⁺ contributes +2 charge).
- The charge from the 1 mole of oxygen is -2 (since each O contributes -2 charge).

4. **Setting Up the Equation**:
- The equation for charge neutrality can be set up as follows:
\[ 3x + 2(0.93 - x) - 2 = 0 \]

5. **Simplifying the Equation**:
- Expanding the equation gives:
\[ 3x + 1.86 - 2x - 2 = 0 \]
- Simplifying further:
\[ x - 0.14 = 0 \]
- Thus, we find:
\[ x = 0.14 \]

6. **Calculating the Fraction of Fe³⁺**:
- The fraction of iron present as Fe³⁺ can be calculated using:
\[ \text{Fraction of Fe³⁺} = \frac{x}{\text{Total Fe}} = \frac{0.14}{0.93} \]
- Performing the division:
\[ \text{Fraction of Fe³⁺} \approx 0.1505 \]

### Final Answer:
The fraction of iron present in the form of Fe(III) is approximately **0.1505**.