Find the strongest acid among the following compound

Options

A. `HOOC-(CH_(2))_(2)-COOH`
B. `overset(+)NH_3-(CH_(2))_(2)-COOH`
C. `F-(CH_(2))_(2)-COOH`
D. `CH_(3)-(CH_(2))_(2)-COOH`

Explanation

To determine the strongest acid among the given compounds, we need to analyze the structures of the compounds and their ability to donate protons (H⁺ ions). Here’s a step-by-step solution:

### Step 1: Identify the Functional Groups
All the compounds mentioned in the question have a carboxylic acid group (COOH), which is responsible for their acidic nature. We need to compare their acidity based on the substituents attached to the carboxylic acid group.

### Step 2: Understand Acid Strength
The strength of an acid is determined by how easily it can donate a proton (H⁺). The more stable the conjugate base formed after the donation of H⁺, the stronger the acid.

### Step 3: Evaluate Electron Withdrawing Groups
Electron withdrawing groups (EWGs) stabilize the negative charge on the conjugate base, making it easier for the acid to donate a proton. The presence of strong EWGs increases the acidity of the compound.

### Step 4: Analyze Each Compound
- **Compound A (COOH)**: This compound has no strong electron withdrawing groups. Therefore, it will have a moderate acidity.

- **Compound B (NH3⁺ attached to COOH)**: The presence of the positively charged NH3⁺ group acts as a strong electron withdrawing group. This increases the positive charge density on the hydrogen of the carboxylic acid, making it easier to lose H⁺ and thus increasing its acidity.

- **Compound C (Fluorine attached to COOH)**: Fluorine is an electron withdrawing group, but it is not as strong as the NH3⁺ group. While it does stabilize the conjugate base, it does not do so as effectively as the NH3⁺ group.

### Step 5: Compare Compounds B and C
Between compounds B and C, the NH3⁺ group in compound B is a stronger electron withdrawing group than the fluorine in compound C. Therefore, compound B will be more acidic than compound C.

### Conclusion
Based on the analysis, **Compound B (NH3⁺ attached to COOH)** is the strongest acid among the given compounds.

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