Question

I need help can show teach me how to do them or link a video that's is easy to understand?

Answer 1

Perhaps it will help if we review the definition of pH and pOH.

The relationship between pH and pOH is
pH + pOH = 14
pH = -log[H+] or in water or aqueous solution -log[H3O+]
pOH - -log[OH-] =

That should be all you need plus a calculator that does log and inverse log

For the first one you have
\[[H ^{+}] = 4.5\times10^{-6}\]
pH=-log[4.5xqo^-6] = 5.35
pOH=14-5.35=8.65
[OH-]=10^-8.65 =2.24x10^-9

It looks like you got the right answers so all you need to do is keep doing the math.