Strongest acid among the following is

Options

A. acetic acid
B. `FCH_(2)COOH`
C. `F_(2)CHCOOH`
D. `F_(3)"CC"OOH`

Explanation

To determine the strongest acid among the given compounds, we will analyze the influence of electronegative atoms, specifically fluorine, on the acidity of the compounds.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds mentioned are:
- Acetic acid (CH3COOH)
- FCH2COOH
- F2CHCOOH
- F3CCOOH

2. **Understanding Acidity**: Acidity is influenced by the stability of the conjugate base formed after the acid donates a proton (H+). The more stable the conjugate base, the stronger the acid.

3. **Effect of Fluorine**: Fluorine is highly electronegative and can withdraw electron density from the carboxylate group (COO-) of the acids. This withdrawal stabilizes the negative charge on the conjugate base, making the acid stronger.

4. **Comparing the Compounds**:
- **Acetic Acid (CH3COOH)**: The methyl group (CH3) is electron-donating, which decreases acidity.
- **FCH2COOH**: The presence of one fluorine atom increases acidity compared to acetic acid due to electron-withdrawing effects.
- **F2CHCOOH**: With two fluorine atoms, the acidity is further increased as more electron density is withdrawn from the carboxylate group.
- **F3CCOOH**: This compound has three fluorine atoms, which maximizes the electron-withdrawing effect and stabilizes the conjugate base the most.

5. **Conclusion**: Based on the increasing number of fluorine atoms and their electron-withdrawing effects, F3CCOOH (trifluoroacetic acid) is the strongest acid among the given compounds.

### Final Answer:
The strongest acid among the following is **F3CCOOH** (trifluoroacetic acid).