Determine the pH of 0.1 M NaOH

Question

I need the calculations to figure out the pH of this solution

Answer 1

Recall that pH + pOH = 14

Recall also that [H⁺][OH^-] = 1x10^-14

Finally, recall that pH = -log [H+] and pOH = -log [OH-]

One way to solve this is as follows:

0.1 M NaOH = 0.1 M OH-

pOH = -log [OH-] = -log 0.1

pOH = 1.0

pH + pOH = 14

pH = 14 - pOH = 14 - 1

pH = 13

Another way to solve this is as follows:

[H⁺][OH^-] = 1x10^-14

[H⁺] = 1x10^-14 / [OH^-] = 1x10^-14 / 0.1 = 1x10^-13

pH = -log [H⁺] = -log 1x10^-13

pH = 13