Iron has the lowest oxidation state in

Options

A. `FeSO_(4)`
B. `K_(4)[Fe(CN)_(6)]`
C. `Fe(CO)_(5)`
D. `FeO`

Answer

To determine the lowest oxidation state of iron in the given compounds, we will analyze each compound step by step.

### Step 1: Analyze FeSO4 (Iron(II) sulfate)
- Let the oxidation state of iron be \( x \).
- The sulfate ion (SO4) has a charge of -2.
- The overall charge of the compound is neutral (0).
- The equation can be set up as:
\[ x + (-2) = 0 \]
- Solving for \( x \):
\[ x = +2 \]
- **Hint**: Remember that the charge of the sulfate ion contributes to the overall charge balance.

### Step 2: Analyze K4[Fe(CN)6] (Potassium ferrocyanide)
- Let the oxidation state of iron be \( x \).
- Potassium (K) has an oxidation state of +1. There are 4 potassium ions, contributing +4.
- The cyanide ion (CN) has an oxidation state of -1. There are 6 cyanide ions, contributing -6.
- The overall charge of the compound is neutral (0).
- The equation can be set up as:
\[ 4 + x + (-6) = 0 \]
- Solving for \( x \):
\[ x = +2 \]
- **Hint**: Keep track of the contributions from all ions in the compound.

### Step 3: Analyze Fe(CO)5 (Iron pentacarbonyl)
- Let the oxidation state of iron be \( x \).
- Carbon monoxide (CO) is a neutral ligand, contributing 0.
- The overall charge of the compound is neutral (0).
- The equation can be set up as:
\[ x + 0 = 0 \]
- Solving for \( x \):
\[ x = 0 \]
- **Hint**: Neutral ligands do not contribute to the oxidation state.

### Step 4: Analyze FeO (Iron(II) oxide)
- Let the oxidation state of iron be \( x \).
- Oxygen has an oxidation state of -2.
- The overall charge of the compound is neutral (0).
- The equation can be set up as:
\[ x + (-2) = 0 \]
- Solving for \( x \):
\[ x = +2 \]
- **Hint**: Remember that oxygen typically has a -2 charge in compounds.

### Conclusion
After analyzing all the compounds:
- In FeSO4, the oxidation state of iron is +2.
- In K4[Fe(CN)6], the oxidation state of iron is +2.
- In Fe(CO)5, the oxidation state of iron is 0.
- In FeO, the oxidation state of iron is +2.

The lowest oxidation state of iron among these compounds is found in **Fe(CO)5**, where the oxidation state is **0**.

### Final Answer
Iron has the lowest oxidation state in **Fe(CO)5** (Iron pentacarbonyl).