Which of the following changes take place during roasting ?
(i) Impurities are removed as they form volatile oxides.
(ii) Ore is converted into their volatile oxides.
(iii) Changes like oxidation , chlorination, etc. take place

Options

A. (i) and (ii)
B. (ii) and (iii)
C. (i) and (iii)
D. (i), (ii) and (iii)

Answer

To solve the question regarding the changes that take place during roasting, we can analyze each statement provided in the question. Here’s a step-by-step breakdown:

### Step 1: Understanding Roasting
Roasting is a metallurgical process used to extract metals from their ores. It involves heating the ore in the presence of excess air (oxygen). This process leads to various chemical reactions.

**Hint:** Roasting is primarily about heating ores with oxygen.

### Step 2: Analyzing Statement (i)
**Statement (i): Impurities are removed as they form volatile oxides.**
- During roasting, impurities present in the ore can react with oxygen to form volatile oxides, which can then be removed from the system. This statement is true.

**Hint:** Consider how impurities behave when heated with oxygen.

### Step 3: Analyzing Statement (ii)
**Statement (ii): Ore is converted into their volatile oxides.**
- This statement is misleading. While the ore is converted into metal oxides during roasting, not all ores are converted into volatile oxides. Typically, the metal itself is converted into a stable oxide form, not necessarily a volatile one. Therefore, this statement is false.

**Hint:** Think about the end products of the roasting process.

### Step 4: Analyzing Statement (iii)
**Statement (iii): Changes like oxidation, chlorination, etc. take place.**
- Roasting involves oxidation reactions where the metal in the ore is oxidized to form metal oxides. Other reactions, such as chlorination, can also occur depending on the specific conditions and materials involved. Thus, this statement is true.

**Hint:** Identify the types of chemical reactions that occur during roasting.

### Step 5: Conclusion
After analyzing all three statements:
- Statement (i) is true.
- Statement (ii) is false.
- Statement (iii) is true.

Thus, the correct answer is that statements (i) and (iii) are true, while statement (ii) is false. Therefore, the correct option that includes the true statements is option D, which states that 1, 2, and 3 are correct.

**Final Answer:** Option D: 1, 2, and 3 are correct.