| Term | Definition |
| NH4+ | always soluble |
| NO3- | always soluble |
| ClO3- | always soluble |
| C2H3O2- | always soluble |
| Salts containing Group 1A elements | always soluble |
| ClO4- | always soluble |
| Cl- | always soluble except APH (Ag+, Pb+2, Hg2+) |
| SO42- | always soluble except CBS (Ca2+, Ba2+, Sr2+) and PBS (Pb2+) |
| Br- | always soluble except APH (Ag+, Pb+2, Hg2+) |
| OH- | always soluble except Group 1A, and CBS (Ca+2, Ba+2, Sr+2) |
| PO4-3 | insoluble except NH4+ and Group 1A |
| S-2 | insoluble except NH4+ and Group 1A |
| CO3-2 | insoluble except NH4+ and Group 1A |
| SO3-2 | insoluble except NH4+ and Group 1A |
| O-2 | insoluble except NH4+ and Group 1A |