`pK_(a)` of a weak acid is 5.76 and `pK_(b)` of a weak base is 5.25. What will be the pH of the salt formed by the two ?

Options

A. 7.255
B. 7.005
C. 10.225
D. 4.255

Explanation

To find the pH of the salt formed by a weak acid and a weak base, we can use the following formula:

\[ \text{pH} = 7 + \frac{1}{2} (\text{pK}_a - \text{pK}_b) \]

### Step-by-Step Solution:

1. **Identify the given values**:
- pK_a of the weak acid = 5.76
- pK_b of the weak base = 5.25

2. **Substitute the values into the formula**:
\[ \text{pH} = 7 + \frac{1}{2} (5.76 - 5.25) \]

3. **Calculate the difference between pK_a and pK_b**:
\[ 5.76 - 5.25 = 0.51 \]

4. **Calculate half of the difference**:
\[ \frac{1}{2} \times 0.51 = 0.255 \]

5. **Add this value to 7**:
\[ \text{pH} = 7 + 0.255 = 7.255 \]

### Final Answer:
The pH of the salt formed by the weak acid and weak base is **7.255**.

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