What is the pOH of a 0.001 M HCl solution?

1 Answer
May 15, 2017

Well, we know that pH+pOH=14, so..............

pOH=11

Explanation:

For the autoprotolysis reaction:

2H2O(l)H3O++HO,

we know that Kw=[H3O+][HO]=1014 under standard conditions............

And taking log10 of both sides we gets............

log10Kw=log101014=log10[H3O+]+log10[HO]

And thus log10[H3O+]log10[HO]=log101014=14

But by definition, log10[H3O+]=pH, and log10[HO]=pOH

So................

pH+pOH=14

You will not be asked to reproduce this as a first year student or as an A-level student. You will be asked (as you have been here!) to use the relationship.

And [HO]=1011molL1.