Is each compound soluble or insoluble? For the soluble compounds, identify the ions present in solution.
Solubility of any compound can be identified by the interaction between polar water molecules and the ions which make up the crystal.
There are certain rules which help us to determine the solubility of any substance in water. These rules are given below:
- All salts of the group I elements (alkali metals = Na, Li, K, Cs, Rb) are soluble.
- All nitrates (NO3-) are soluble.
- Chlorate (ClO3-), perchlorate (ClO4-), and acetate (CH3COO-) salts are soluble.
- All chlorides, bromides, and iodides are soluble except those of silver, mercury, and lead (e.g., AgCl, Hg2Cl2, and PbCl2).
- Most sulfates are soluble. Exceptions include BaSO4, PbSO4, and SrSO4
- All carbonates are insoluble except NH4+ and those of the group I elements.
- All hydroxides are insoluble except those of the Group 1 elements. Ba(OH)2, Sr(OH)2 and Ca(OH)2 are slightly soluble.
- All sulfides are insoluble except those of the Group 1 and group II elements and NH4+
- Phosphates are frequently insoluble except those of the Group 1 elements and NH4+.