Chapter 17 Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria - Study Questions - Page 677c: 63

(a) $PbS$ (b) $Ag_2CO_3$ (c) $Al(OH)_3$

If a salt contains an anion that can act as a base, it will be more soluble in acidic solutions. (a) $S^{2-}$ is a base, and $Cl^-$ isn't. (b) $CO_3^{2-}$ is a base, but $I^-$ isn't, (c) $OH^-$ is a base, but $Cl^-$ isn't.