At 25 °C, what is the hydroxide ion concentration, [OH−] , in an aqueous solution with a hydrogen ion concentration of [H+]=3.0×10−8 M?

Explanation:

Hello,

In this case, for the given concentration of hydronium, we can compute the pH as shown below:

Now, given the relationship between pH and pOH we can compute the pOH which is directly related with the concentration of hydroxyl in the solution:

Then, the concentration of hydroxyl turns out:

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