In the given reaction
`RCN underset((ii)H_2O //H^+)overset((i)RMgX)rarr(X)`, (X) will be

Options

A. Aldehyde
B. Ketone
C. Tertiary alcohol
D. Secondary alcohol

Answer

To solve the given reaction step by step, we will analyze the reaction involving an alkyl cyanide (RCN) and a Grignard reagent (RMgX), followed by hydrolysis.

### Step 1: Identify the Reactants
The reactants in the reaction are:
- Alkyl cyanide (RCN)
- Grignard reagent (RMgX)

### Step 2: Reaction of Alkyl Cyanide with Grignard Reagent
When the Grignard reagent (RMgX) reacts with the alkyl cyanide (RCN), the nucleophilic alkyl group (R-) from the Grignard reagent attacks the carbon atom of the cyanide group (C≡N). This leads to the formation of an intermediate compound.

**Intermediate Formation:**
- The carbon atom of the cyanide group becomes bonded to the alkyl group (R), and the nitrogen atom carries a negative charge, resulting in the formation of an imine-like structure (R-C(=N)-MgX).

### Step 3: Hydrolysis of the Intermediate
The next step involves hydrolysis of the formed intermediate. When the intermediate is treated with water (H2O) in the presence of an acid (H+), the imine undergoes hydrolysis.

**Hydrolysis Process:**
- The imine structure reacts with water, breaking the C=N bond and forming a carbonyl compound (ketone) and releasing the nitrogen as ammonium ion (NH4+).

### Step 4: Final Product
The final product after hydrolysis is a ketone (R-C(=O)-R'), where R' is the original alkyl group from the cyanide.

### Conclusion
Thus, the product (X) formed in the reaction is a ketone.

### Answer
(X) will be a ketone.

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