The reaction of methane with iodine is carried out in the presence of `"HIO"_(3)` because `"HIO"_(3)`:

Options

A. Gives iodine in the iodination of methane
B. Oxidises HI formed in the reaction
C. Reduces HI formed is the reaction
D. Changes the `l_(2)` molecule into I atoms.

Answer

To solve the question regarding the role of HIO3 in the reaction of methane with iodine, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding the Reaction**: The reaction between methane (CH4) and iodine (I2) produces methyl iodide (CH3I) and hydrogen iodide (HI). This reaction can be represented as:
\[ CH_4 + I_2 \rightleftharpoons CH_3I + HI \]
This reaction is reversible, meaning that HI can react with methyl iodide to regenerate methane.

2. **Role of HI**: In this reaction, HI acts as a strong reducing agent. It can reduce methyl iodide (CH3I) back to methane (CH4), which creates a challenge in achieving a good yield of methyl iodide because the reaction can shift back to the left.

3. **Introducing HIO3**: To prevent the reverse reaction (the conversion of CH3I back to CH4), a strong oxidizing agent is introduced. HIO3 (iodic acid) serves this purpose.

4. **Function of HIO3**: HIO3 oxidizes the HI produced in the reaction. The oxidation of HI leads to the formation of iodine (I2) and water (H2O). The reaction can be summarized as:
\[ 3HI + HIO_3 \rightarrow 3H_2O + I_2 \]
By oxidizing HI, HIO3 effectively removes HI from the equilibrium, driving the reaction towards the formation of more methyl iodide.

5. **Conclusion**: Therefore, the primary function of HIO3 in the reaction of methane with iodine is to oxidize HI formed during the reaction, preventing it from reverting methyl iodide back to methane.

### Final Answer:
HIO3 is used in the reaction of methane with iodine because it oxidizes the HI produced in the reaction to I2, thereby preventing the reverse reaction and promoting the formation of methyl iodide.