Final answer:
Potassium, sodium, and ammonium salts, including K2S, K2SO4, Li2S, Na2C3O2, and NH4Cl, are soluble. Lead, mercury, and silver salts, such as PbSO4, Hg2I2, Hg2Cl2, and sulfides of heavy metals and Group II elements, including BaS, Cu3(PO4)2, MgS, and SrS, are insoluble. BaSO4 is also insoluble, whereas PbCl2 is soluble.
Step-by-step explanation:
The solubility of compounds is an essential concept in chemistry that determines whether a compound will dissolve in a given solvent. According to solubility rules, potassium (K+), ammonium (NH4+), and sodium (Na+) salts are generally soluble, making K₂S, K₂SO₄, Li2S, Na₂C₃O₂ (presumed typo for Na2CO3), and NH₄Cl soluble. Most sulfate (SO4^2-) salts are soluble, with some exceptions such as barium (BaSO4), lead (PbSO4), calcium (CaSO4), and strontium (SrSO4) being either fully or slightly insoluble.
Heavy metal compounds, like lead, mercury, and silver salts, are frequently insoluble, indicating that PbSO₄, Hg₂I2, and Hg2Cl₂ are insoluble. Sulfides (S^2-) of transition metals and Group II elements tend to be insoluble, making BaS, Cu₃(PO₄)2, MgS, SrS insoluble while PbCl₂ is the exception, being soluble.