Chem- Solubility Rules

1. Always soluble compounds (no exceptions)

• Group 1 cations (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺)

• Nitrates (NO₃⁻)

• Ammonium (NH₄⁺)

• Acetates (CH₃COO⁻ or C₂H₃O₂⁻)

• Chlorates (ClO₃⁻)

• Perchlorates (ClO₄⁻)

• Bicarbonates (HCO₃⁻)

2. Soluble with basic exceptions

• All Chlorides (Cl-): EXCEPTIONS→ AgCl, Hg2Cl2, HgCl, PbCl2

• All Bromides (Br-): EXCEPTIONS→ AgBr, Hg2Br2, HgBr2, PbBr2

• All iodides (I-): EXCEPTIONS→ AgI, Hg2I2, HgI2, PbI2

3. Sulfates (SO4(-2))

soluble, EXCEPT→ CaSO4, SrSO4, BaSO4, Ag2SO4, Hg2SO4, HgSO4, PbSO4

4. Monovalent Metals

Monovalent metals are metals that typically form +1 cations (M⁺) — meaning they lose one electron to achieve a stable electron configuration.

• Phosphates (PO4(-3))

• Carbonates (CO3(-2))

• All metallic oxides (O(-2))

• metalic hydroxides (OH(-)

  Are insoluble, EXCEPT→ NH4(+) and Group 1 cations (alkali metals).

8. all sulfides (S(-2))

insoluble, EXCEPT→ NH4(+), Group 1A cations (alkali metals), Group 2 Metals (alkaline earth metals) – slightly to moderately soluble