When diethyl ether is treated with excess of `CI_(2)` in the presence of sum light, the product formed is :

Options

A. `CH_(3)CHCI-O-CH_(2)CH_(3)`
B. `CH_(3)CHCI-O-CHCICH_(3)`
C. `C CI_(3)C CI_(2)-O-C CI_(2)C CI_(3)`
D. `CH_(3)C CI_(2)-O-CHCICH_(3)`.

Explanation

To solve the question regarding the reaction of diethyl ether with excess chlorine in the presence of sunlight, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactant is diethyl ether, which has the chemical formula \( CH_3CH_2OCH_2CH_3 \).
- The other reactant is chlorine gas (\( Cl_2 \)).

2. **Understand the Reaction Conditions**:
- The reaction takes place in the presence of sunlight, which indicates that this is a photochemical reaction. Sunlight provides the energy needed to initiate the reaction.

3. **Mechanism of Reaction**:
- In the presence of sunlight, chlorine can undergo homolytic cleavage, producing chlorine radicals (\( Cl \cdot \)).
- These radicals can then abstract hydrogen atoms from diethyl ether, leading to a substitution reaction where hydrogen atoms are replaced by chlorine atoms.

4. **Substitution of Hydrogen Atoms**:
- Diethyl ether has a total of 10 hydrogen atoms (from the two ethyl groups).
- When treated with excess \( Cl_2 \), all 10 hydrogen atoms can be substituted by chlorine atoms.

5. **Formation of Products**:
- The complete substitution of all hydrogen atoms by chlorine results in the formation of a compound with the formula \( C_2Cl_5O \) (since the ether oxygen remains intact).
- The final product can be represented as \( CCl_3CH_2OCH_2CCl_3 \) or \( Cl_2C-O-CCl_2CCl_3 \).

6. **By-products**:
- Along with the main product, hydrogen chloride (\( HCl \)) is also formed as a by-product due to the substitution of hydrogen atoms.

7. **Final Product Representation**:
- The final product can be summarized as:
\[ CCl_3CH_2OCH_2CCl_3 + 10 HCl \]

8. **Conclusion**:
- Therefore, the product formed when diethyl ether is treated with excess \( Cl_2 \) in the presence of sunlight is a fully chlorinated ether along with hydrogen chloride.

### Answer:
The product formed is \( CCl_3CH_2OCH_2CCl_3 \) (fully chlorinated diethyl ether) along with \( HCl \).