The addition of high proportions of maganese makes steel useful in making rails or railroads because manganese

Options

A. Gives hardness to steel
B. Helph in the formation of oxides of iron
C. Can remove oxygen and sulphur
D. Can show the highest oxidation state of `+7`

Explanation

To solve the question regarding the addition of high proportions of manganese in steel and its usefulness in making rails or railroads, we will analyze the properties of manganese and its effects on steel.

### Step-by-Step Solution:

1. **Understanding the Role of Manganese in Steel:**
- Manganese is an essential alloying element in steel. It is known for enhancing the mechanical properties of steel, particularly its hardness and strength.

**Hint:** Consider the properties of manganese that contribute to the overall quality of steel.

2. **Formation of Slag:**
- Manganese has the ability to react with impurities such as sulfur and oxygen present in steel. When manganese is added, it forms manganese oxides and sulfides, which can be removed from the steel as slag during the steel-making process.

**Hint:** Think about how impurities affect the quality of steel and how manganese interacts with these impurities.

3. **Chemical Reactions Involved:**
- The reaction of iron oxide (Fe2O3) with manganese can be represented as:
\[ \text{Fe}_2\text{O}_3 + 3\text{Mn} \rightarrow 3\text{MnO} + 2\text{Fe} \]
- Additionally, manganese can react with silicon dioxide (SiO2) to form manganese silicate (MnSiO3), which also contributes to the removal of impurities.

**Hint:** Recall the chemical reactions that occur during the steel-making process and how they relate to the properties of the final product.

4. **Evaluating the Options:**
- The question provides several options regarding the effects of manganese on steel:
- (a) Manganese gives hardness to steel.
- (b) Manganese helps in the formation of oxide of iron.
- (c) Manganese can remove oxygen and sulfur.
- (d) Manganese can show the highest oxidation state of +7.

- From our analysis:
- Option (a) is correct because manganese indeed increases the hardness of steel.
- Option (b) is incorrect as manganese does not primarily aid in the formation of iron oxides.
- Option (c) is correct since manganese removes oxygen and sulfur by forming slag.
- Option (d) is incorrect as manganese does not exhibit a +7 oxidation state in steel applications.

**Hint:** Cross-reference the properties and reactions of manganese with the provided options to determine which statements are true.

5. **Conclusion:**
- The correct statements regarding the addition of manganese in steel are:
- Manganese gives hardness to steel.
- Manganese can remove oxygen and sulfur by forming slag.

### Final Answer:
The addition of high proportions of manganese makes steel useful in making rails or railroads because manganese gives hardness to steel and also removes oxygen and sulfur from steel by forming slag.