Give structural formula of `alpha,alpha`-Dibromopropanoic acid.

Explanation

To derive the structural formula of alpha,alpha-Dibromopropanoic acid, we can follow these steps:

### Step 1: Identify the Base Structure
- The name "propanoic acid" indicates that the base structure is a three-carbon chain (propane) with a carboxylic acid (-COOH) group at one end.

### Step 2: Draw the Carbon Chain
- Draw a straight chain of three carbon atoms:
```
C1 - C2 - C3
```

### Step 3: Add the Carboxylic Acid Group
- At the end of the chain (C1), add the carboxylic acid group (-COOH):
```
C1 (COOH) - C2 - C3
```

### Step 4: Identify the Alpha Position
- The alpha position refers to the carbon atoms adjacent to the carboxylic acid group. In this case, C2 is the alpha position.

### Step 5: Add Bromine Atoms
- The prefix "alpha-alpha-dibromo" indicates that there are two bromine atoms attached to the alpha position (C2). Therefore, we add two bromine atoms to C2:
```
C1 (COOH) - C2 (Br) - C3 (Br)
```

### Step 6: Complete the Valency of Carbon Atoms
- Each carbon atom must have four bonds.
- C1 (with -COOH) has one bond to the -COOH and needs three more hydrogen atoms.
- C2 (with two Br atoms) has two bonds to the Br atoms and needs two more hydrogen atoms.
- C3 needs three hydrogen atoms to complete its valency.

Putting it all together, we can represent the structure as follows:
```
Br
|
H3C-C-COOH
|
Br
```

### Final Structural Formula
The final structural formula of alpha,alpha-Dibromopropanoic acid is:
```
Br
|
H3C-C(Br)-COOH
```