pK, value of trifluoroacetic acid, benzoic acid and acetic acid are respectively

Options

A. 4.76, 4:19 and 0:23
B. 4-19, 4-76 and 0-23
C. 0-23, 4-76 and 4-19
D. 0:23, 4-19 and 4.76

Answer

To find the pK_a values of trifluoroacetic acid, benzoic acid, and acetic acid, we can follow these steps:

### Step 1: Understand the concept of pK_a
The pK_a value is a measure of the acidity of a compound. It is calculated using the formula:
\[ pK_a = -\log K_a \]
where \( K_a \) is the acid dissociation constant.

### Step 2: Identify the acids and their structures
1. **Trifluoroacetic acid**: The chemical formula is \( CF_3COOH \).
2. **Benzoic acid**: The chemical formula is \( C_6H_5COOH \) (a benzene ring with a carboxylic acid group).
3. **Acetic acid**: The chemical formula is \( CH_3COOH \).

### Step 3: Memorize or look up the pK_a values
- **Trifluoroacetic acid** has a pK_a of approximately **0.23**.
- **Benzoic acid** has a pK_a of approximately **4.20**.
- **Acetic acid** has a pK_a of approximately **4.75**.

### Step 4: Write the final answer
The pK_a values of trifluoroacetic acid, benzoic acid, and acetic acid are respectively:
- Trifluoroacetic acid: **0.23**
- Benzoic acid: **4.20**
- Acetic acid: **4.75**

### Final Answer:
The pK_a values are: **0.23, 4.20, 4.75**.

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