Question

What is the pH of a solution having a hydrogen ion concentration of 1x10^-5 M?

Also the same question, but Hydroxide instead of hydrogen.

thanks in advance!

Answer 1

You do these in your head.
pH = -log(H^+) = -log(1E-5) = 5
pOH then is 14-5 = 9

pH = -log(H^+)
pOH = -log(OH^-)
pH + pOH = pKw = 14
and (H^+)(OH^-) = Kw = 1E-14
These three will take care of any
pH/pOH/H^+/OH^- problems you will ever have.