Question

What is the hydroxide ion concentration of a lye solution that has a ph of 9.20?

Answer 1

Explanation:

It is known that relation between pH and hydrogen ion concentration is as follows.

                 pH = $-log [H^{+}]$

As pH is given 9.20 so, calculate the hydrogen ion concentration as follows.

                    pH = $-log [H^{+}]$

                 9.20 = $-log [H^{+}]$

           antilog (-9.20) = $[H^{+}]$

                $[H^{+}] = 6.31 \times 10^{-10}$

As, relation between hydroxide ions and hydrogen ions is as follows.

                $[H^{+}] \times [OH^{-}] = 10^{14}$

                  $6.31 \times 10^{-10} \times [OH^{-}] = 10^{14}$

                 $[OH^{-}] = \frac{10^{14}}{6.31 \times 10^{-10}}$  

              $[OH^{-}] = 1.58 \times 10^{23}$

Thus, we can conclude that the hydroxide ion concentration of a lye solution that has a pH of 9.20 is $1.58 \times 10^{23}$.      

Answer 2

To determine what the OH concentration is of a solution with a pH of 9.20. Simply remember that both the pH and POH add up to give a value equal to the ionization exponential value for water, which is 14.

Simply subtract 14 and 9.2 to find the pOH and then take the inverse log to find the OH concentration.

POH = 4.8

OH concentration = 1.58 X 10^-5 M.