...hheeelp plzzz?? ​

9

Explanation:

n-factor of NaOH = 1

OH⁻ concentration = Normality of NaOH

                             = Molarity x n-factor

                             = 10⁻⁵ x 1

                             = 10⁻⁵  

Now, pOH = -㏒(OH⁻)

        pOH = -㏒(10⁻⁵)

        pOH = 5

We know pH + pOH = 14

               pH = 14 - 5 = 9

∴pH of 10⁻⁵M NaOH is 9

its first and third is your answer i did the qustion the fourth isnt right