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The set having incorrect statement is ...

The set having incorrect statement is
1. the Hall-Heroult process is used for the production of aluminum and iron
2. pig iron is obtained from cast iron.
3. the blistered appearance of copper during the metallurgical process is due to the evolution of `CO_2`
4. leaching of bauxite using concentrated NaOH solution gives sodium aluminate and sodium silicate

A

1,2

B

2,3

C

1,2,3

D

1,2,4

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze each statement provided and determine which ones are incorrect. ### Step-by-Step Solution: 1. **Statement 1**: "The Hall-Heroult process is used for the production of aluminum and iron." - **Analysis**: The Hall-Heroult process is specifically used for the production of aluminum from alumina (Al₂O₃) through electrolysis. It does not produce iron. Therefore, this statement is **incorrect**. 2. **Statement 2**: "Pig iron is obtained from cast iron." - **Analysis**: Pig iron is produced directly from the blast furnace and is the intermediate product from which cast iron is made. Cast iron is produced by melting pig iron and adding other elements. Thus, this statement is also **incorrect**. 3. **Statement 3**: "The blistered appearance of copper during the metallurgical process is due to the evolution of CO₂." - **Analysis**: The blistered appearance of copper is actually due to the evolution of sulfur dioxide (SO₂) during the Bessemerization process, not carbon dioxide (CO₂). Hence, this statement is **incorrect**. 4. **Statement 4**: "Leaching of bauxite using concentrated NaOH solution gives sodium aluminate and sodium silicate." - **Analysis**: This statement is correct. During the leaching of bauxite with concentrated sodium hydroxide (NaOH), sodium aluminate and sodium silicate are formed, and impurities are removed. Therefore, this statement is **correct**. ### Conclusion: The statements that are incorrect are 1, 2, and 3. Therefore, the set having incorrect statements is **1, 2, and 3**. ### Final Answer: The set having incorrect statements is **1, 2, 3**. ---
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