Which of the following is the most impure form of iron ?

Options

A. Bessemer iron
B. Steel
C. Pig iron
D. Wrought iron

Answer

To determine which of the following is the most impure form of iron, we need to analyze the options provided: Bessemer iron, steel, pig iron, and wrought iron.

### Step-by-Step Solution:

1. **Understanding Bessemer Iron**:
- Bessemer iron is produced through the Bessemer process, which converts pig iron into steel by removing impurities.
- Since the process aims to purify the iron, Bessemer iron is not considered impure.
- **Conclusion**: Bessemer iron is a relatively pure form of iron.

**Hint**: Remember that processes designed to remove impurities lead to purer forms of the element.

2. **Analyzing Steel**:
- Steel typically consists of about 98-99% iron and 1% carbon.
- The small amount of carbon present is considered an impurity, but it is minimal compared to other forms of iron.
- **Conclusion**: Steel has low impurity levels.

**Hint**: Consider the percentage of carbon as an indicator of impurity in iron alloys.

3. **Examining Pig Iron**:
- Pig iron contains a higher carbon content, generally around 3-4%, along with other impurities like sulfur.
- This higher carbon content makes pig iron significantly more impure compared to steel and wrought iron.
- **Conclusion**: Pig iron has a higher level of impurities.

**Hint**: Higher carbon content usually indicates a more impure form of iron.

4. **Looking at Wrought Iron**:
- Wrought iron contains very low levels of impurities, typically around 0.08% carbon.
- This makes wrought iron one of the purest forms of iron.
- **Conclusion**: Wrought iron is not impure.

**Hint**: The lower the carbon content, the purer the form of iron.

5. **Final Comparison**:
- Bessemer iron: relatively pure.
- Steel: low impurity (1% carbon).
- Pig iron: high impurity (3-4% carbon).
- Wrought iron: very low impurity (0.08% carbon).
- **Conclusion**: Among all the options, pig iron has the highest level of impurities.

### Final Answer:
The most impure form of iron is **Pig Iron**.