Final answer:
Solubility of ionic compounds in water depends on the specific cations and anions they contain.
Step-by-step explanation:
Solubility of Ionic Compounds
Certain cations and anions form compounds that are usually soluble in water. All compounds of alkali metal cations like Li+, Na+, K+, Rb+, Cs+, and ammonium (NH4+) have no exceptions and are soluble. When it comes to anions, salts containing nitrate (NO3−), acetate (CH3COO−), and perchlorate (ClO4−) ions are also universally soluble without exceptions.
However, there are exceptions to the solubility of certain ions. For example, bromides, chlorides, and iodides are typically soluble unless they're paired with cations like Pb2+, Hg22+, or Ag+. Similarly, sulfates (SO42−) are generally soluble except when in combination with the same set of cations or with heavy alkaline earth metals such as Ca2+, Sr2+, and Ba2+.
Certain ions are typically insoluble, with some exceptions based on the cation they are paired with. For instance, hydroxides (OH−) and sulfides (S2−) are insoluble unless they are combined with an alkali metal, ammonia, or specified heavy alkaline earth metals. Similarly, carbonates (CO32−), phosphates (PO43−), and oxides are commonly insoluble, except with alkali metal or ammonium cations.
Alkali metal and ammonium cations, as well as nitrate, acetate, and perchlorate anions, form soluble compounds without exceptions. Other ions like sulfates, halides, and hydroxides have exceptions based on the cation they are paired with.