Question

What is the pH of a 0.10 M solution of barium hydroxide, `Ba(OH)_2`?

Express your answer using two decimal places.

Answer 1

`"pH"=13.30`.

Explanation:

Barium hydroxide is a strong base for both stages of dissociation:

`"Ba"("OH")_2(s) -> "Ba"^{2+}+2"OH"^-`

So the solution will have 0.20 M hydroxide ions. Now use the autodissociation product for water:

`["H"^+]["OH"^-]=1.0xx10^{-14}"M"^`
`["OH"^-]=2.0xx10^{-1}"M"`
`["H"^+]=5.0xx10^{-14}"M"`

And then

`"pH"=-log_{10}(["H"^+]=5.0xx10^{-14})=13.30`.