The reagent used for the conversion `CH_(3)CH_(2)COOH rarrCH_(3)CH_(2)CH_(3)`, is

Options

A. `LiAlH_(4)`
B. soda lime
C. red P and concentrated Hl
D. amalgamated zinc and concentrated HCl

Explanation

To convert the carboxylic acid CH₃CH₂COOH (pentanoic acid) into the alkane CH₃CH₂CH₃ (propane), we need to follow these steps:

### Step 1: Identify the Functional Groups
The starting compound, CH₃CH₂COOH, is a carboxylic acid due to the presence of the -COOH group. The target compound, CH₃CH₂CH₃, is an alkane, which contains only carbon and hydrogen atoms with single bonds.

### Step 2: Determine the Type of Reaction
The conversion from a carboxylic acid to an alkane involves the reduction of the carboxylic acid. This means we need a reagent that can effectively remove the -COOH group and replace it with hydrogen atoms.

### Step 3: Select the Appropriate Reagent
The reagent that can facilitate this conversion is red phosphorus (P) in the presence of concentrated hydroiodic acid (HI). This combination is known to reduce carboxylic acids to alkanes.

### Step 4: Write the Reaction
The reaction can be represented as follows:
\[ \text{CH}_3\text{CH}_2\text{COOH} \xrightarrow{\text{red P + HI}} \text{CH}_3\text{CH}_2\text{CH}_3 \]

### Step 5: Conclusion
Thus, the reagent used for the conversion of CH₃CH₂COOH to CH₃CH₂CH₃ is red phosphorus and concentrated hydroiodic acid (HI).

### Final Answer
The reagent used for the conversion is **red phosphorus + concentrated HI**.

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