What is the colour of vapours obtained when an iodide is heated with conc. `H_(2)SO_(4)` ?

Answer

To determine the color of vapors obtained when an iodide is heated with concentrated sulfuric acid (H₂SO₄), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
We start with an iodide, which can be represented as potassium iodide (KI) in this case, and concentrated sulfuric acid (H₂SO₄).

2. **Write the Reaction**:
When potassium iodide (KI) is heated with concentrated sulfuric acid, the following reaction occurs:
\[ 2 \text{KI} + \text{H}_2\text{SO}_4 \rightarrow 2 \text{KHSO}_4 + \text{H}_2\text{O} + \text{SO}_2 + \text{I}_2 \]
Here, potassium hydrogen sulfate (KHSO₄), water (H₂O), sulfur dioxide (SO₂), and iodine (I₂) are produced.

3. **Understand the Role of Iodide**:
Iodide ions (I⁻) act as strong reducing agents when heated with concentrated sulfuric acid, leading to the formation of free iodine (I₂).

4. **Identify the Color of Iodine Vapors**:
The iodine produced in the reaction is in the form of vapors. The color of iodine vapors is known to be violet.

5. **Conclusion**:
Therefore, when an iodide is heated with concentrated sulfuric acid, the color of the vapors obtained is violet.

### Final Answer:
The color of the vapors obtained when an iodide is heated with concentrated sulfuric acid is violet.

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