The `pK_(a)` of acetic acid is 4.74 . The concentration of `CH_(3)C O O H ` is 0.01 M. The pH of `CH_(3) C O O H` is

Options

A. 3.37
B. 4.37
C. 4.74
D. 0.474

Explanation

To find the pH of a 0.01 M solution of acetic acid (CH₃COOH) given that its pKₐ is 4.74, we can use the following steps:

### Step-by-Step Solution:

1. **Identify the given values**:
- pKₐ of acetic acid = 4.74
- Concentration of acetic acid (C) = 0.01 M

2. **Use the formula for pH of a weak acid**:
The formula to calculate the pH of a weak acid is:
\[ \text{pH} = \frac{1}{2} \times \text{pK}_a - \log C \]

3. **Substitute the known values into the formula**:
\[ \text{pH} = \frac{1}{2} \times 4.74 - \log(0.01) \]

4. **Calculate \(\log(0.01)\)**:
\[ \log(0.01) = \log(10^{-2}) = -2 \]

5. **Substitute \(\log(0.01)\) back into the pH equation**:
\[ \text{pH} = \frac{1}{2} \times 4.74 - (-2) \]
\[ \text{pH} = \frac{4.74}{2} + 2 \]
\[ \text{pH} = 2.37 + 2 \]
\[ \text{pH} = 4.37 \]

6. **Final result**:
The pH of the 0.01 M acetic acid solution is approximately **4.37**.