Question

What is the concentration of hydroxide ions in a solution with a pH of 12.6?

a) [OH-] = 10^-12.6
b) [OH-] = 2.51 × 10^-13 M
c) [OH-] = 3.98 × 10^-2 M'

Answer 1

The concentration of hydroxide ions ([OH-]) in a solution with a pH of 12.6 is 3.98 × 10^-2 M. This is found by subtracting the given pH from 14 to get the pOH, and then using the pOH to calculate [OH-].

Step-by-step explanation:

To find the concentration of hydroxide ions in a solution with a pH of 12.6, we must first recall that pH and pOH are related by the equation pH + pOH = 14. Since we know the pH, we can calculate the pOH:

pOH = 14 - pH = 14 - 12.6 = 1.4

Now that we have the pOH, we can find the hydroxide ion concentration ([OH-]) using the relationship pOH = -log[OH-], which can be rewritten as [OH-] = 10^(-pOH).

Therefore, the concentration of hydroxide ions is:

[OH-] = 10^(-1.4) = 3.98 × 10^-2 M

So the correct answer to the question is c) [OH-] = 3.98 × 10^-2 M.