J.R. S. answered 03/27/22
Ph.D. University Professor with 10+ years Tutoring Experience
Here are the relationships you need to know:
pH + pOH = 14
[H+][OH-] = 1x10-14
pH = -log [H+]
pOH = -log [OH-]
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pH = 10.10
[H+] = 1x10-10.10 = 7.94x10-11
[OH-] = 1x10-14 / 7.94x10-11 = 1.26x10-4
pOH = -log 1.26x10-4 = 3.90
or
pOH = 14 - pH = 14 - 10.10 = 3.9