To find the pH of a solution with a hydroxide ion concentration of [tex]\(2.20 \times 10^{-8} \, M\)[/tex], follow these steps:
1. Determine the pOH:
The pOH can be calculated using the formula:
[tex]\[
\text{pOH} = -\log[\text{OH}^-]
\][/tex]
Substituting the given hydroxide ion concentration:
[tex]\[
\text{pOH} = -\log(2.20 \times 10^{-8}) \approx 7.66
\][/tex]
2. Calculate the pH:
The relationship between pH and pOH in aqueous solutions at room temperature (25°C) is given by:
[tex]\[
\text{pH} + \text{pOH} = 14
\][/tex]
Using the calculated pOH:
[tex]\[
\text{pH} = 14 - \text{pOH} = 14 - 7.66 = 6.34
\][/tex]
Based on this calculation, the pH of the solution with a [tex]\(2.20 \times 10^{-8} \, M\)[/tex] hydroxide ion concentration is [tex]\(6.34\)[/tex].
Therefore, the correct answer from the given choices is:
- 6.34
