The number of carbon atoms in the principle chain of the given compound are :-
`CH_(3) - CH_(2) - CH_(2) - undersetunderset(OHC-CH_2-CH_(2) -CH_(3))(|)CH-COOH`

Options

A. 7
B. 5
C. 4
D. 6

Answer

To determine the number of carbon atoms in the principal chain of the given compound, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure**: The compound is given as `CH₃ - CH₂ - CH₂ - (OHC - CH₂ - CH₂ - CH₃)`, where `OHC` indicates an aldehyde group (–CHO) and `COOH` indicates a carboxylic acid group (–COOH).

2. **Determine Functional Groups**: The functional groups present are:
- A carboxylic acid group (–COOH)
- An aldehyde group (–CHO)

3. **Identify the Principal Chain**: The principal chain is the longest continuous chain of carbon atoms that includes the highest priority functional group. In this case, the carboxylic acid (–COOH) has a higher priority than the aldehyde (–CHO).

4. **Number the Carbon Atoms**: Start numbering the carbon chain from the end nearest to the carboxylic acid group:
- Start from the carbon of the carboxylic acid (position 1).
- Continue counting the carbon atoms in the chain:
- 1 (COOH) - 2 (next carbon) - 3 (next carbon) - 4 (next carbon) - 5 (next carbon).
- This gives us a total of 5 carbon atoms in the principal chain.

5. **Conclusion**: The number of carbon atoms in the principal chain of the given compound is 5.

### Final Answer:
The number of carbon atoms in the principal chain of the given compound is **5**.

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