Assertion: Roasting is a process in which the ore is heated in presence of air Reason: Concentration of sulphide ore is done by calcination

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion .
B. if both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Explanation

To analyze the given question, we will break down the assertion and reason provided, and evaluate their correctness step by step.

### Step 1: Understanding the Assertion
- **Assertion**: Roasting is a process in which the ore is heated in the presence of air.
- **Evaluation**: This statement is **correct**. Roasting is indeed a process where metal sulfides are heated in the presence of air (or oxygen) to convert them into metal oxides, releasing sulfur dioxide gas. For example, when zinc sulfide (ZnS) is roasted, it forms zinc oxide (ZnO) and sulfur dioxide (SO2).

### Step 2: Understanding the Reason
- **Reason**: Concentration of sulfide ore is done by calcination.
- **Evaluation**: This statement is **incorrect**. Calcination is a process used primarily for carbonate ores, where they are heated in the absence of air to drive off carbon dioxide (CO2) and leave behind metal oxides. For example, heating calcium carbonate (CaCO3) results in calcium oxide (CaO) and CO2. Sulfide ores, on the other hand, are concentrated through roasting, not calcination.

### Step 3: Conclusion
- Since the assertion is correct and the reason is incorrect, we conclude that:
- **Assertion**: True
- **Reason**: False

Thus, the correct answer to the question is that the assertion is true, but the reason is false.

### Final Answer
- **Assertion**: True
- **Reason**: False