`X+CH_(3)MgBr-overset(H_(2)O)_to CH_(3)COCH_(3)+NH_(3)+Mg(OH)` Identify X

Options

A. ethyl cyanide
B. ethyl chlorde
C. ethane nitrile
D. methane nitrile

Answer

To identify compound X in the reaction given, we will analyze the reaction step by step.

### Step 1: Understand the Reaction
The reaction is represented as:
\[ X + CH_3MgBr \overset{H_2O}{\rightarrow} CH_3COCH_3 + NH_3 + Mg(OH)Br \]
Here, \( CH_3MgBr \) is a Grignard reagent, and upon hydrolysis with water, it produces a ketone, ammonia, and magnesium hydroxide bromide.

### Step 2: Identify the Products
The product \( CH_3COCH_3 \) is known as acetone, which is a ketone with the structure:
\[ CH_3 - C(=O) - CH_3 \]
This indicates that the ketone has three carbon atoms in total.

### Step 3: Analyze the Carbon Atoms
From the Grignard reagent \( CH_3MgBr \), we can see that it contributes one carbon atom (the \( CH_3 \) group). Therefore, for the final product to have three carbon atoms, compound X must contribute the remaining two carbon atoms.

### Step 4: Determine the Structure of X
Since X must provide two carbon atoms and also allow for the evolution of ammonia gas (\( NH_3 \)), we can deduce that X must contain a carbon-nitrogen bond (specifically a nitrile group, \( -C \equiv N \)).

### Step 5: Identify Possible Candidates for X
We will consider the possible candidates:
1. Ethyl cyanide (\( CH_3CH_2C \equiv N \)): This has two carbon atoms and a nitrile group.
2. Ethyl chloride (\( CH_3CH_2Cl \)): This has two carbon atoms but does not contain a nitrile group.
3. Ethyl nitride (\( CH_3C \equiv N \)): This has two carbon atoms and a nitrile group.
4. Hydrogen cyanide (\( HCN \)): This has only one carbon atom.

### Step 6: Select the Correct Compound
From the candidates:
- Ethyl cyanide (\( CH_3CH_2C \equiv N \)) and ethyl nitride (\( CH_3C \equiv N \)) both contain the required two carbon atoms and a nitrile group.
- Ethyl chloride does not produce ammonia upon reaction, so it is not a valid candidate.
- Hydrogen cyanide does not provide enough carbon atoms.

### Step 7: Confirm the Correct Structure
The most suitable candidate for X is ethyl cyanide (\( CH_3CH_2C \equiv N \)). When it reacts with the Grignard reagent, the nucleophilic attack will lead to the formation of acetone, ammonia, and magnesium hydroxide bromide.

### Conclusion
Thus, the compound X is:
\[ \text{X} = \text{Ethyl cyanide (CH}_3CH_2C \equiv N\text{)} \]

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