Dimethyl ether when heated with exces HI gives :

Options

A. `CH_(3) I and CH_(3) OH`
B. `CH_(3) I and H_(2) O`
C. `C_(2) H_(6) +CH_(3) I and CH_(3) OH`
D. `CH_(3) I and HCHO`

Answer

To solve the problem of what happens when dimethyl ether (CH3OCH3) is heated with excess hydrogen iodide (HI), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: We start with dimethyl ether, which has the chemical formula CH3OCH3.

2. **Understand the Reaction with HI**: When dimethyl ether is heated with hydrogen iodide (HI), it undergoes cleavage. The ether bond (C-O) is broken, and the ether is converted into alkyl iodides and alcohol.

3. **Reaction with Excess HI**: When there is excess HI, the reaction proceeds further. The ether will first react to form methyl iodide (CH3I) and methanol (CH3OH):
\[ CH3OCH3 + HI \rightarrow CH3I + CH3OH \]

4. **Further Reaction of Methanol**: Since HI is in excess, the produced methanol (CH3OH) can further react with HI to produce more methyl iodide:
\[ CH3OH + HI \rightarrow CH3I + H2O \]

5. **Overall Reaction**: Combining these reactions, we can summarize the overall reaction when dimethyl ether is heated with excess HI:
\[ CH3OCH3 + 2 HI \rightarrow 2 CH3I + H2O \]

### Final Products:
The final products when dimethyl ether is heated with excess HI are:
- Methyl iodide (CH3I)
- Water (H2O)