`alpha`-hydroxy propanoic aic has ……….. , asymmetric carbon atoms .

Options

A. 4
B. 3
C. 2
D. 1

Explanation

To determine the number of asymmetric carbon atoms in alpha-hydroxypropanoic acid, we will follow these steps:

### Step 1: Understand the Structure of Alpha-Hydroxypropanoic Acid
Alpha-hydroxypropanoic acid, also known as lactic acid, has the following structure:

```
OH
|
H3C-C-COOH
|
H
```

### Step 2: Identify the Carbon Atoms
In the structure, we have three carbon atoms:
1. The first carbon (C1) is part of the methyl group (CH3).
2. The second carbon (C2) is the central carbon that is attached to the hydroxyl group (OH), a hydrogen atom (H), and the carboxylic acid group (COOH).
3. The third carbon (C3) is part of the carboxylic acid group (COOH).

### Step 3: Determine Which Carbon Atoms are Asymmetric
An asymmetric (or chiral) carbon atom is defined as a carbon atom that is bonded to four different groups.

- **C1 (Methyl group)**: It is attached to three hydrogen atoms (H3C), so it is not asymmetric.
- **C2 (Central carbon)**: It is attached to:
- A hydroxyl group (OH)
- A hydrogen atom (H)
- A carboxylic acid group (COOH)
- A methyl group (CH3)

Since C2 is bonded to four different groups, it is an asymmetric carbon atom.
- **C3 (Carboxylic carbon)**: It is part of the carboxylic acid (COOH) and is double-bonded to oxygen, so it is not asymmetric.

### Step 4: Conclusion
Based on the analysis, alpha-hydroxypropanoic acid has **one asymmetric carbon atom**.

### Final Answer:
Alpha-hydroxypropanoic acid has **1 asymmetric carbon atom**.

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