alkali metals (Group IA) compounds
always soluble
Ammonium (NH4+) compounds
always soluble
Nitrates (NO3-), Acetates (C2H302-), Chlorates (ClO3-), Perchlorates (Cl04-)
always soluble
Most Chlorides (Cl-), Bromides (Br-), Iodides
exceptions include:
soluble
(exceptions for compounds containing Ag+, Hg+, PB+2)
Most sulfates (SO4^-3)
exceptions include:
soluble
(CaSO4, SrSO4, and Ag2SO4 are slightly soluble)
(BaSO4, HgSO4 and PbSO4 are insoluble)
Most hydroxides (OH-)
and exceptions include:
insoluble
(The exceptions are the alkali metal hydroxides and Ba(OH)2).
(The alkaline earth metals like Ca(OH)2 is slightly soluble)
Carbonates (CO3-2), phosphates (PO4-3), chromates (CrO42-), fluorides (F-), and sulfides (S-2)
exceptions include:
usually insoluble
The exceptions are the alkali metals and the ammonium ion (NH4+)
Ag+ compounds
exceptions include:
insoluble
exceptions are AgNO3 and AgC2H3O2