A solution of NaOH was prepared in a chemistry lab and the pOH was determined to be 9.3. What is the concentration of OH⁻ ions of this basic solution?

• A. 5 × 10⁻¹¹ M
• B. 5 × 10⁻¹⁰ M
• C. 2 × 10⁹ M
• D. 2 × 10⁸ M

Answer: (B)

Verified step by step guidance

1. Understand that pOH is a measure of the hydroxide ion concentration in a solution. It is related to the concentration of OH⁻ ions by the formula: \( \text{pOH} = -\log[\text{OH}^-] \).
2. To find the concentration of OH⁻ ions, rearrange the formula to solve for \([\text{OH}^-]\): \([\text{OH}^-] = 10^{-\text{pOH}}\).
3. Substitute the given pOH value into the equation: \([\text{OH}^-] = 10^{-9.3}\).
4. Calculate \(10^{-9.3}\) to find the concentration of OH⁻ ions in moles per liter (M).
5. Compare the calculated concentration with the provided options to determine the correct answer.