Question

Select the correct statement :

• A. Roasting involves heating the ore in the absence of air
• B. Calcination involves heating the ore above its melting point
• C. Smelting involves heating the ore with suitable reducing agent and flux below its melting point
• D. Calcination of calcium carbonate is endothermic

Answer 1

The Correct Option is D

• Roasting: This process involves heating the ore in the presence of air (not in the absence of air), so option (A) is incorrect.
• Calcination: This process involves heating an ore below its melting point, not above. It is used to drive off volatile components, like water or carbon dioxide, from the ore. So option (B) is incorrect.
• Smelting: This process involves heating the ore with a reducing agent and flux, but it is typically done above the melting point to extract the metal. So option (C) is incorrect.
• Calcination of calcium carbonate: When calcium carbonate (CaCO₃) is heated, it decomposes into calcium oxide (CaO) and carbon dioxide (CO₂). This is an endothermic reaction, meaning it requires heat to proceed. Hence, option (D) is correct.

Thus, calcination of calcium carbonate is endothermic because it absorbs heat during the decomposition process.

The correct answer is (D) Calcination of calcium carbonate is endothermic.

Answer 2

- Roasting is heating the ore in the presence of oxygen.  
- Calcination involves heating the ore below its melting point in the absence of air, not above the melting point.  
- Smelting is the process of heating the ore with a reducing agent and flux to extract the metal.  
- The process of calcination of calcium carbonate (CaCO₃) to produce lime (CaO) and carbon dioxide is endothermic because it requires heat absorption.