The first disinfectant used by Joseph Lister was called carbolic acid.This substance now is known as phenol, C₆H₅OH (pK_a = 9.90).What is the pH of a 0.10 M solution of phenol?

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Quizplus · Accepted Answer

To find the pH of a 0.10 M solution of phenol, we use the formula for the dissociation of a weak acid: $$pH = \frac{1}{2}(pKa - \log[C_{acid}])$$. Given that the $pKa$ of phenol is 9.90 and the concentration ($C_{acid}$) is 0.10 M, we plug these values into the formula: $$pH = \frac{1}{2}(9.90 - \log[0.10]) = \frac{1}{2}(9.90 - (-1)) = \frac{1}{2}(10.90) = 5.45.$$

The First Disinfectant Used by Joseph Lister Was Called Carbolic