Here are some commonly used solubility rules:

• Most nitrate (NO3-) salts and compounds containing alkali metals (Group 1 elements) and ammonium (NH4+) are soluble in water.

• Most salts of alkali earth metals (Group 2 elements) are soluble, except for those containing sulfates (SO42-), carbonates (CO32-), chromates (CrO42-), and phosphates (PO43-).

• Most chlorides (Cl-), bromides (Br-), and iodides (I-) are soluble, except for those of silver (Ag+), lead (Pb2+), and mercury (Hg22+).

• Most sulfates (SO42-) are soluble, except for those of barium (Ba2+), strontium (Sr2+), lead (Pb2+), calcium (Ca2+), and silver (Ag+).

• Most hydroxides (OH-) are insoluble, except for those of alkali metals (Group 1 elements) and barium (Ba2+), which are moderately soluble. Calcium (Ca2+), strontium (Sr2+), and some transition metals form slightly soluble hydroxides.

• Most carbonates (CO32-) and phosphates (PO43-) are insoluble, except for those of alkali metals (Group 1 elements) and ammonium (NH4+).

• Most sulfides (S2-) are insoluble, except for those of alkali metals (Group 1 elements), ammonium (NH4+), and some alkaline earth metals.