Solubility Rules

Solubility rules help predict whether an ionic compound will dissolve in water not

Soluble

dissolves in water

Insoluble

does not dissolve in water

Dissociation:

When ionic compounds (metal and non-metal) dissolve, the ions (the metal ion and the non-metal ion) physically separate from each other.

Hydrated

ions that are now separated from each other

and completely surrounded by water

Electrolyte

Any substance which produces separate ions in water.

Group 1, alkali metals, and ammonium (NH₄+)

soluble

Nitrates (NO₃-), Chlorates (ClO₃-), Perchlorates (ClO₄-), and Acetates (C₂H₃O₂)-:

soluble

Hydroxides (OH-)

insoluble, exceptions…

exception of insolubility for hydroxides

alkali metal hydroxides, and Ba(OH)₂

Ca(OH)₂ slightly soluble

Chlorides, Bromides, and Iodides

soluble, exceptions…

exception of solubility for Cl, Br, and I?

compounds with Ag⁺, Hg⁺², Pb⁺²

Carbonates (CO₃^-2) Phosphates (PO₄^-3) and Sulfides (S^-2)

insoluble, exceptions…

exception of insolubility for Carbonates, Phosphates, and Sulfides

alkali metals and ammonium ion

Sulfates (SO₄^-2)

soluble …

exception of soluibily for Sulfates

CaSO₄ and Ag₂SO₄ are slightly soluble

BaSO₄, HGSO₄, PbSO₄ are insoluble