When there's a weak base substance (hydrophobic powder), and it needs to be completely protonated by adding an acid (eg: HCl), how does one know when it's completely protonated? Since the powdered base substance isn't soluble until protonated, doesn't that mean that it won't be reflected when measuring the pH (via the commonly used pH test strips)?
I'm under the impression that when the base is suspended in water, as HCl is added and given time to react, the pH would float round 7 or 8. Then when it's fully protonated, the pH will start to dip below 7, which would mean there's now an excess of HCl since there's nothing for it to bind with, which would be too much.
I don't exactly have a specific substance base substance in mind. This is more a general question about acid-base reactions involving a solid base.