# How is silver chloride more soluble in brine than water?

I heard that:

Silver chloride is more soluble in very concentrated NaCl solution (brine) than in pure water.

Is it true? I mean won't the common ion effect operate? Or may be this is due to some kind of complex formation as NaCl solution is highly concentrated ???

• Yes silver will form a complex, $\ce{AgCl2-}$ – MaxW Oct 7 '18 at 6:10

Exactly, before your ionic equation was: $$\ce{Ag+ (aq) + Cl- (aq) <=> AgCl (s)}$$ but with brine, the ionic equation is: $$\ce{AgCl (s) + Cl- (aq) <=> [AgCl2]- (aq)}$$ Which has a different solubility constant, and where as before more chloride made the $$\ce{AgCl}$$ less soluble, if you note that you have switched regimes and $$\ce{Cl-}$$ has switched from being a reactant to a product, which means now with additional chloride silver chloride becomes more soluble.