For preparing a buffer solution of pH 6 by mixing sodium acetate and acetic acid, the ratio of the concentration of salt and acid should be (Ka = 10^(-5))
A. 1:10
B. 10:1
C. 100:1
D. 1:100

To solve this, we need to use the **Henderson-Hasselbalch equation**, which relates the pH of a buffer solution to the concentrations of the weak acid and its conjugate base (salt):

\[
\text{pH} = \text{pKa} + \log \left( \frac{[\text{Salt}]}{[\text{Acid}]} \right)
\]

Where:
- pH = 6 (as given)
- pKa = \(-\log K_a = -\log (10^{-5}) = 5\)
- \(\frac{[\text{Salt}]}{[\text{Acid}]}\) is the ratio we need to find.

Now, substitute the values into the Henderson-Hasselbalch equation:

\[
6 = 5 + \log \left( \frac{[\text{Salt}]}{[\text{Acid}]} \right)
\]

Subtract 5 from both sides:

\[
1 = \log \left( \frac{[\text{Salt}]}{[\text{Acid}]} \right)
\]

Now, exponentiate both sides to eliminate the logarithm:

\[
10^1 = \frac{[\text{Salt}]}{[\text{Acid}]}
\]

\[
10 = \frac{[\text{Salt}]}{[\text{Acid}]}
\]

Thus, the ratio of the concentration of salt to acid should be **10:1**.

### Correct Answer: **B. 10:1**