NAG SAG - Solubility Rules
NAG SAG: Nitrates, Acetates, Group 1 Always Soluble; Ammonium is Good
The easiest solubility rules to remember: all nitrates, all acetates, all Group 1 (alkali metal) compounds, and all ammonium compounds are soluble in water.
Breakdown
Nitrates (NO3-)
All nitrates are soluble
Acetates (CH3COO-)
All acetates are soluble
Group 1
Li, Na, K, Rb, Cs compounds all soluble
Soluble
These will dissolve in water
Ammonium (NH4+)
All ammonium salts are soluble
Good
You can count on these rules!
Example
AgNO3 is soluble (nitrate rule). NaCl is soluble (Group 1 rule). But AgCl is insoluble (exception to Cl- usually being soluble). BaSO4 is insoluble (exception to sulfates).
When to Use This
- ✓Predicting precipitation reactions
- ✓Writing net ionic equations
- ✓Qualitative analysis
- ✓Preparing solutions
FAQs
Common questions about this mnemonic
Common insoluble exceptions: AgCl, PbCl2, Hg2Cl2 (chlorides); BaSO4, PbSO4, CaSO4 (sulfates); most hydroxides except Group 1 and Ba(OH)2; most sulfides, carbonates, and phosphates except with Group 1/NH4+.
Mix two ionic solutions and imagine swapping cations. If either product is NOT in NAG SAG and isn't a common exception, check if it's insoluble - if so, it precipitates!