Indicate the expected structure of the organic product when ethyl magnesium bromide is treated with heavy water `(D_(2)O)` -

Options

A. `C_(2)H_(5)–C_(2)H_(5)`
B. `C_(2)H_(5)OD`
C. `C_(2)H_(6)`
D. `C_(2)H_(5)D`

Answer

To determine the expected structure of the organic product when ethyl magnesium bromide is treated with heavy water (D₂O), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- Ethyl magnesium bromide (C₂H₅MgBr) is a Grignard reagent. It consists of an ethyl group (C₂H₅) bonded to magnesium bromide.

2. **Understanding the Nature of Grignard Reagents**:
- Grignard reagents are nucleophilic, meaning they have a negative charge on the carbon atom bonded to magnesium. In this case, the ethyl group can be represented as C₂H₅⁻ (where the negative charge is on the carbon).

3. **Reaction with Heavy Water**:
- Heavy water (D₂O) contains deuterium (D), which is an isotope of hydrogen. When ethyl magnesium bromide reacts with heavy water, the nucleophilic ethyl group will attack the deuterium in D₂O.

4. **Formation of the Product**:
- The reaction can be represented as:
\[ C₂H₅MgBr + D₂O \rightarrow C₂H₅D + MgBr(OH) \]
- Here, the ethyl group (C₂H₅⁻) will bond with one of the deuterium atoms (D) from D₂O, resulting in the formation of deuterated ethane (C₂H₅D).

5. **Final Structure of the Organic Product**:
- The final organic product is deuterated ethane, which can be represented as:
\[ \text{C₂H₅D} \]
- The by-product of the reaction is magnesium bromide hydroxide (MgBr(OH)).

### Expected Structure:
The expected structure of the organic product is:
```
H D
\ /
C
/ \
H H
|
C
|
H
```
This represents deuterated ethane (C₂H₅D).