The compound (A) in the following reaction sequence is:
(A) `overset(PCl_(5))(rarr) " (B) " overset("Alc KOH")(rarr) " ( C) " overset(H_(2)// Ni )(rarr)`
Propane :

Options

A. Chloroethane
B. Ethanol
C. 1,2-Dichloroethane
D. None of the above

Answer

To determine the compound (A) in the reaction sequence leading to propane, we can analyze the reactions step by step.

### Step 1: Identify the Reaction with PCl5
The first reaction involves compound (A) reacting with phosphorus pentachloride (PCl5). PCl5 is known to convert alcohols into alkyl chlorides through a nucleophilic substitution reaction. This suggests that compound (A) is likely an alcohol.

### Step 2: Determine the Structure of Compound (A)
Since the final product of the reaction sequence is propane (C3H8), we can deduce that compound (A) must be an alcohol with a three-carbon chain. The possible structures for a three-carbon alcohol are:
- 1-Propanol (propyl alcohol)
- 2-Propanol (isopropyl alcohol)

### Step 3: Reaction of Alcohol with PCl5
When either 1-propanol or 2-propanol reacts with PCl5, it will produce:
- 1-Propanol → 1-Chloropropane (B)
- 2-Propanol → 2-Chloropropane (B)

Both reactions will yield alkyl chlorides.

### Step 4: Reaction with Alcoholic KOH
Next, the alkyl chloride (B) reacts with alcoholic KOH. This reaction is an elimination reaction (dehydrohalogenation) that will produce an alkene:
- 1-Chloropropane → Propene (C)
- 2-Chloropropane → Propene (C)

In both cases, the product is propene (C3H6).

### Step 5: Hydrogenation of Alkene
Finally, the propene (C) undergoes hydrogenation in the presence of hydrogen and nickel, resulting in propane (C3H8).

### Conclusion
Since both 1-propanol and 2-propanol can lead to the formation of propane through the given reaction sequence, we conclude that compound (A) must be either 1-propanol or 2-propanol. However, since the question does not provide specific options for alcohols, we can assert that compound (A) is a three-carbon alcohol.

### Final Answer
Compound (A) is either 1-Propanol or 2-Propanol.

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