The carboxyl functional group`(-COOH)` is present in:

Options

A. picric acid
B. barbituric acid
C. ascorbic acid
D. aspirin

Explanation

To determine which of the given compounds contains the carboxyl functional group (-COOH), we can analyze the structures of each compound mentioned in the question. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Compounds
We have four compounds to analyze:
1. Picric acid
2. Barbituric acid
3. Ascorbic acid
4. Aspirin

### Step 2: Draw the Structures
For each compound, we will draw its structure to identify the presence of the carboxyl group (-COOH).

#### 1. Picric Acid
- Structure: It has a benzene ring with three nitro groups (NO2) and one hydroxyl group (OH).
- Carboxyl Group: **Absent**

#### 2. Barbituric Acid
- Structure: It has a six-membered ring with nitrogen atoms and double bonds.
- Carboxyl Group: **Absent**

#### 3. Ascorbic Acid
- Structure: It has a five-membered ring with multiple hydroxyl (OH) groups.
- Carboxyl Group: **Absent**

#### 4. Aspirin
- Structure: It has a benzene ring with an ester group (O=C-O) and a carboxyl group (-COOH).
- Carboxyl Group: **Present**

### Step 3: Conclusion
After analyzing the structures of all four compounds, we find that only **Aspirin** contains the carboxyl functional group (-COOH).

### Final Answer
The carboxyl functional group (-COOH) is present in **Aspirin**.

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