Yeah what elfspice said.
When pseudoepehdrine is 'freebase', it is NOT an acid. So it is not pseudoepehdrine sulfate or pseudoepehdrine hydrochloride or anything. It is just called 'freebase' pseudoepehdrine.
Freebase pseudoepehdrine is not soluble in water.
Pseudoepehdrine hydrochloride or sulfate IS soluble in water.
If this freebase pseudoepehdrine is exposed to acid, it will take on that acid and become a salt. Meaning, if the pseudoepehdrine freebase is exposed to hydrochloric acid, it will become pseudoepehdrine hydrochloride. OR is it's exposed to sulfuric acid (
), it will become pseudoepehdrine sulfate.
And acid/base extraction involves -
-turning the pseudo in to a freebase form (wether it was pseudo HCl or pseudo sulfate), and
-turning it into a salt. We are interested in the hydrochloride salt, so we use hydrochloric acid, and we make
pseudoepehdrine hydrochloride. Regardless of it starting form, this is what we end up with.