Ch 4 AP Chemsitry Solubility rules

Rule 1: Ammonium & Group 1A

ALWAYS SOLUBLE. All salts of ammonium (NH4+) and Group 1A alkali metals (Li+, Na+, K+, Rb+, Cs+) are soluble with no exceptions.

Rule 2a: Chlorides (Cl-)

SOLUBLE, EXCEPT AgCl, Hg2Cl2, and PbCl2.

Rule 2b: Bromides (Br-)

SOLUBLE, EXCEPT AgBr, Hg2Br2, HgBr2, and PbBr2.

Rule 2c: Iodides (I-)

SOLUBLE, EXCEPT AgI, Hg2I2, HgI2, and PbI2.

Halides Shortcut (Cl-, Br-, I-)

All Halides are soluble EXCEPT when paired with Heavy Metals: Silver (Ag+), Mercury (Hg2 2+ / Hg2+), or Lead (Pb2+).

Rule 3: Chlorates, Nitrates, Acetates

ALWAYS SOLUBLE. Chlorates (ClO3-), Nitrates (NO3-), and Acetates (CH3COO-) have no exceptions.

Rule 4: Sulfates (SO4 2-)

SOLUBLE, EXCEPT CaSO4, SrSO4, BaSO4, Hg2SO4, HgSO4, PbSO4, and Ag2SO4.

Sulfates Exception Mnemonic

"CaStRo Bear" (Ca2+, Sr2+, Ba2+) plus Heavy Metals (Hg2 2+, Hg2+, Pb2+, Ag+).

Rule 5: Phosphates & Carbonates

INSOLUBLE, EXCEPT when paired with NH4+ or Group 1A metals.

Rule 6: Metallic Oxides (O 2-)

INSOLUBLE, EXCEPT when paired with NH4+ or Group 1A metals.

Rule 7: Metallic Hydroxides (OH-)

INSOLUBLE, EXCEPT NH4+, Group 1A, and Group 2A from Calcium down (Ca2+, Sr2+, Ba2+).

Rule 8: Sulfides (S 2-)

INSOLUBLE, EXCEPT NH4+, Group 1A, and ALL Group 2A metals.