Question

The ph of a basic solution is 12.81. what is [oh⁻]?

Answer 1

The hydroxide ion concentration, [OH⁻], for a basic solution with a pH of 12.81 is approximately 6.46 × 10⁻² M. This is found by subtracting the pH from 14 to get the pOH and then using the inverse logarithmic relationship to calculate [OH⁻].

Step-by-step explanation:

To find the hydroxide ion concentration, [OH⁻], for a solution with a pH of 12.81, we utilize the relationship between pH and pOH which is pH + pOH = 14. First, calculate the pOH by subtracting the pH from 14:

pOH = 14 - pH = 14 - 12.81 = 1.19

Now, to find the hydroxide ion concentration, we can use the following formula:

[OH⁻] = 10⁻(pOH) = 10⁻¹¹⁹

Performing the calculation:

[OH⁻] = 10⁻¹¹⁹ ≈ 6.46 × 10⁻² M

The hydroxide ion concentration of a solution with a pH of 12.81 is approximately 6.46 × 10⁻² M. Since the pH is greater than 7, this indicates we are working with a basic solution.