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assume that for the pH 9.2 phenolphthalein sample, you used half as much phenolphthalein solution (i.e your sample is 9 ml buffer, 0.5 ml phenophthalein solution and 0.5 ml water). what should happen to the value of Kc you determine?

Respuesta :

Explanation:

It is given that pH is equal to 9.2. So, we will calculate the value of [tex]pK_{a}[/tex] as follows.

        pH = [tex]pK_{a} + log \frac{[H_{3}O^{+}]}{[\text{solution}]}[/tex]

Putting the given values into the above formula as follows.

    pH = [tex]pK_{a} + log \frac{[H_{3}O^{+}]}{[\text{solution}]}[/tex]

      [tex]pK_{a} = pH - log \frac{\frac{1}{0.5}}{\frac{1}{10}}[/tex]

                  = 7.9

             [tex]K_{a} = 10^{7.9}[/tex]

                       = [tex]1.26 \times 10^{-8}[/tex]

Since, the value of [tex]K_{a}[/tex] comes out to be positive. This means that there will occur an increase in the value of [tex]K_{a}[/tex] or [tex]K_{c}[/tex].