Solubility of AgCl

Illustration showing the solubility of AgCl, S_AgCl, as a function of pCl. The dashed red line shows S_AgCl if one assumes incorrectly that the only relevant reaction is

AgCl(s) ↔ Ag⁺(aq) + Cl^–(aq)

The solid blue curve is the actual solubility when considering additional reactions forming soluble silver-chloro complexes

Ag⁺(aq) + Cl^–(aq) ↔ AgCl(aq)

AgCl(aq) + Cl^–(aq) ↔ AgCl₂^–(aq)

AgCl₂^–(aq) + Cl^–(aq) ↔AgCl₃^2–(aq)

Because the solubility of AgCl spans several orders of magnitude, S_AgCl is displayed on the y-axis in logarithmic form.