The pH of the solution containing 0.1 N HCl and 0.1N `CH_(3)COOH` is

Options

A. 1
B. 0.7
C. 2
D. 1.3

Answer

To find the pH of a solution containing 0.1 N HCl and 0.1 N acetic acid (CH₃COOH), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Strong Acid**:
- HCl is a strong acid and completely dissociates in water. Therefore, the concentration of hydrogen ions (H⁺) from HCl is equal to its normality.
- For 0.1 N HCl, the concentration of H⁺ ions is 0.1 M.

2. **Identify the Weak Acid**:
- Acetic acid (CH₃COOH) is a weak acid and does not completely dissociate in solution. Its dissociation can be represented as:
\[ CH₃COOH \rightleftharpoons H⁺ + CH₃COO⁻ \]
- The dissociation constant (Ka) for acetic acid is approximately \(1.8 \times 10^{-5}\).

3. **Calculate the Contribution of Acetic Acid**:
- The concentration of acetic acid is 0.1 M. However, due to the presence of a strong acid (HCl), the dissociation of acetic acid will be suppressed due to the common ion effect.
- Since H⁺ from HCl is significantly higher than that from acetic acid, we can assume that the contribution of H⁺ from acetic acid is negligible.

4. **Determine the pH**:
- Since the contribution of H⁺ from acetic acid is negligible, the pH of the solution can be calculated using only the H⁺ concentration from HCl.
- The pH is calculated using the formula:
\[ \text{pH} = -\log[H⁺] \]
- Substituting the concentration of H⁺ from HCl:
\[ \text{pH} = -\log(0.1) = 1 \]

### Final Answer:
The pH of the solution containing 0.1 N HCl and 0.1 N acetic acid is **1**.