Hi guys
First of all, sorry if I've posted this in the wrong section, I'm new here
I have a (potentially dumb) problem which I hoped you could help me with. It's about the common-ion effect. Here's my line of thought, I would really appreciate it if someone could point out where my logic fails:
1. The common-ion effect states that the solubility of a salt will decrease if more ions common to the ones in the salt are added.
2. The definition of solubility, according to my book, is the concentration of a salt in a saturated solution.
3. According to Le Châtelier's principle, if we add eg Ag+ ions in a AgCl - solution, we will "push" the equilibrium so that more of the salt, AgCl, is produced.
4. So, I can't force it into my head that the concentration of a salt increases while its solubility decreases, seeing as the definition says the concentration of a salt (in a saturated solution) equals the salt's solubility.
If one of you manage to convince me, or tell me where I'm wrong, then you should really be a teacher! It's like trying to learn a monkey physics
Hope there's someone here that can help me!
TuAst