Solubility Rules
Quick reference for predicting precipitation. When a combination is insoluble, a solid forms and can be isolated.
| Group | Soluble? | Exceptions |
|---|---|---|
| Group 1 (alkali) & NH₄⁺ | Always soluble | None |
| Nitrates, acetates, perchlorates | Soluble | None |
| Chlorides, bromides, iodides | Soluble | Ag⁺, Pb²⁺, Hg₂²⁺ |
| Sulfates | Soluble | Ba²⁺, Pb²⁺, Ca²⁺, Sr²⁺ |
| Group | Soluble? | Exceptions |
|---|---|---|
| Carbonates, phosphates | Insoluble | Group 1, NH₄⁺ |
| Hydroxides | Insoluble | Group 1, NH₄⁺, Ba²⁺, Sr²⁺, Ca²⁺ sparingly |
| Sulfides | Insoluble | Group 1, NH₄⁺, Group 2 sparingly |
These are guidelines; borderline solubility is temperature dependent and defined by Ksp. See [Solubility and Precipitation](/topics/solubility-precipitation) and Ksp.
SOURCES
- [tro-chemistry]Chemistry: Structure and Properties (2023). Pearsonhttps://www.pearson.com/