ANSWER
The pH is 7.302
EXPLANATION
Given that
[tex]\text{ \lbrack OH}^-\text{ \rbrack }=\text{ 2.0 }\times\text{ 10}^{-7}[/tex]Follow the steps below to find the the pH
Step 1; Write the formula for calculating pOH
[tex]\text{ pOH = -log \lbrack OH}^-\text{ \rbrack}[/tex]Step 2; Substitute the value of [OH^-] = 2.0 x 10 ^-7
[tex]\begin{gathered} \text{ pOH = -log \lbrack 2.0 }\times\text{ 10}^{-7\text{ }}\text{ \rbrack} \\ \text{ pOH = 6.698} \end{gathered}[/tex]Recall, that pH + pOH = 14
Hence, we can find pH
[tex]\begin{gathered} \text{ pH + pOH = 14} \\ \text{ pH + 6.698 = 14} \\ \text{ pH = 14 - 6.698} \\ \text{ pH = 7.302} \end{gathered}[/tex]Therefore, the pH is 7.302
