Purest form of commercial iron is :

Options

A. pig iron
B. scrap iron and pig iron
C. wrought iron
D. cast iron

Answer

To determine the purest form of commercial iron from the given options, we will analyze each option step-by-step.

### Step 1: Analyze Cast Iron
- **Definition**: Cast iron is an alloy of iron that typically contains 2% to 4% carbon, along with small amounts of sulfur, phosphorus, silicon, and manganese.
- **Purity**: Since cast iron contains a significant amount of carbon and other impurities, it is not considered pure iron.

**Hint**: Remember that alloys contain other elements, which reduces their purity.

### Step 2: Analyze Wrought Iron
- **Definition**: Wrought iron is known for its low carbon content (less than 0.08%) and is considered to be the purest form of iron.
- **Purity**: Wrought iron is almost pure iron, making it the best candidate for the purest form of commercial iron.

**Hint**: Look for materials with low carbon content to identify purer forms of iron.

### Step 3: Analyze Pig Iron
- **Definition**: Pig iron is produced from smelting iron ore and contains about 4% to 5% carbon along with other impurities.
- **Purity**: Pig iron is considered an impure form of iron and is often used as a raw material for further processing.

**Hint**: Higher carbon content typically indicates a less pure form of iron.

### Step 4: Analyze Scrap Iron
- **Definition**: Scrap iron refers to recycled iron materials that can include various forms of iron and steel, often mixed with impurities.
- **Purity**: Scrap iron is not a pure form of iron as it consists of various iron scraps and alloys.

**Hint**: Recycled materials often contain a mix of different elements, which lowers their purity.

### Conclusion
After analyzing all the options:
- Cast Iron: Not pure
- Wrought Iron: Purest form
- Pig Iron: Impure
- Scrap Iron: Not pure

The purest form of commercial iron is **Wrought Iron**.

**Final Answer**: Wrought Iron