Table 4.1 Simple Rules for the Solubility of Salts in Water.

1. Nitrate, Chlorates and Perchlorates (NO₃^-, ClO₃^-1, ClO₄^-1) salts are soluble.
2. Most salts containing the alkali metal ions-Column IA (Li⁺, Na⁺, K⁺, Cs⁺, Rb⁺) and the ammonium ion (NH₄⁺) are soluble.
3. Acetates (C₂H₃O₂^-1) are all soluble except with Ag⁺¹
4. Most chloride, bromide, and iodide salts are soluble. Notable exceptions are salts containing the ions Ag⁺, Pb²⁺, and Hg₂²⁺ (or Hg⁺¹) and Cu⁺¹.
5. Most sulfate salts are soluble. Notable exceptions are CaSO₄, and below and PbSO₄, Hg₂SO₄.
6. Most hydroxide salts are only slightly soluble. The important soluble hydroxides are Column IA hydroxides (alkali metal hydroxides). The middle compounds of column IIA - Ba(OH)₂, Sr(OH)₂, and Ca(OH)₂ are marginally soluble.
7. Most sulfide (S^2-), carbonate (CO₃^2-), chromate (CrO₄^2-), and phosphate (PO₄^3-) salts are only slightly soluble at best.