The major product of the following chemical reaction is:
`CH_3CH_2CNoverset(overset(((1)H_3O^+,Delta))((2)SOCl_2))underset((3)pd//BaSO_4,H_2)rarr?`

Options

A. `CH_3CH_2CH_3`
B. `CH_3CH_2CH_2OH`
C. `(CH_3CH_2CO)_2O`
D. `CH_3CH_2CHO`

Answer

To solve the given problem, we need to analyze the chemical reaction step by step. The reaction involves a compound with a cyanide group and goes through two main steps: first, the conversion of the cyanide to an aldehyde, and then the reduction of that aldehyde to an alcohol.

### Step 1: Reaction with H3O+ (Hydronium Ion)
The starting compound is `CH3CH2C≡N` (a nitrile). When this compound reacts with `H3O+`, it undergoes hydrolysis. In this step, the cyanide group (C≡N) is converted into an aldehyde (C=O). This reaction is known as the hydrolysis of nitriles.

The reaction can be summarized as follows:
\[ CH_3CH_2C≡N + H_3O^+ \rightarrow CH_3CH_2C(=O)H \]
This gives us the product:
\[ CH_3CH_2CHO \]
which is butanal (an aldehyde).

### Step 2: Reduction with Pd/BaSO4 and H2
In the second step, the aldehyde formed (butanal) is reduced to an alcohol using palladium on barium sulfate (Pd/BaSO4) in the presence of hydrogen gas (H2). This reduction converts the carbonyl group (C=O) of the aldehyde to a hydroxyl group (–OH), yielding a primary alcohol.

The reaction can be summarized as follows:
\[ CH_3CH_2CHO + H_2 \xrightarrow{Pd/BaSO_4} CH_3CH_2CH_2OH \]
This gives us the product:
\[ CH_3CH_2CH_2OH \]
which is butanol (a primary alcohol).

### Final Product
Thus, the major product of the reaction sequence is:
\[ CH_3CH_2CH_2OH \]
which is butanol.

### Summary of Steps:
1. **Hydrolysis of Nitrile**: Convert `CH3CH2C≡N` to `CH3CH2CHO` (butanal).
2. **Reduction of Aldehyde**: Convert `CH3CH2CHO` to `CH3CH2CH2OH` (butanol).