Solubility Chart
The Solubility Chart is a science reference tool covering solubility chart, solubility rules chart, solubility rules, chemical solubility chart. Use the chart below to look up values instantly. Printable and downloadable versions are available on this page.
Solubility Predictor
Select a cation and anion to instantly determine if the compound is soluble, slightly soluble, or insoluble — with the relevant rule cited.
Solubility Chart — Ions in Water
| Ion or Compound Type | Solubility Rule |
|---|---|
| All Group 1 metal compounds (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺) | Soluble No exceptions. |
| All ammonium (NH₄⁺) compounds | Soluble No exceptions. |
| All nitrate (NO₃⁻) compounds | Soluble No exceptions. |
| All acetate (CH₃COO⁻) compounds | Soluble No exceptions. |
| Most chloride (Cl⁻), bromide (Br⁻), iodide (I⁻) compounds | Soluble Except with Ag⁺, Pb²⁺, and Hg₂²⁺. |
| Most sulfate (SO₄²⁻) compounds | Soluble Except with Ba²⁺, Sr²⁺, Ca²⁺, Pb²⁺, and Hg₂²⁺. |
| Most hydroxide (OH⁻) compounds | Insoluble Except with Group 1 metals, Ba²⁺, and Sr²⁺. |
| Most carbonate (CO₃²⁻) compounds | Insoluble Except with Group 1 metals and NH₄⁺. |
| Most phosphate (PO₄³⁻) compounds | Insoluble Except with Group 1 metals and NH₄⁺. |
| Most sulfide (S²⁻) compounds | Insoluble Except with Group 1 metals, Group 2 metals, and NH₄⁺. |
| All oxide (O²⁻) compounds | Insoluble Except with Group 1 metals (react with water to form hydroxides). |
| All chromate (CrO₄²⁻) compounds | Insoluble Except with Group 1 metals, Ca²⁺, Mg²⁺, and NH₄⁺. |
Standard general chemistry solubility rules — see OpenStax Chemistry 2e: Classifying Chemical Reactions
Solubility of Common Compounds — Quick Reference
| Compound | Formula | Solubility |
|---|---|---|
| Sodium chloride table salt | NaCl | Soluble |
| Sodium hydroxide lye | NaOH | Soluble |
| Sodium carbonate washing soda | Na₂CO₃ | Soluble |
| Potassium nitrate | KNO₃ | Soluble |
| Ammonium sulfate | (NH₄)₂SO₄ | Soluble |
| Silver chloride | AgCl | Insoluble Ksp = 1.8 × 10⁻¹⁰ |
| Silver nitrate | AgNO₃ | Soluble |
| Barium sulfate | BaSO₄ | Insoluble Ksp = 1.1 × 10⁻¹⁰ |
| Calcium carbonate limestone | CaCO₃ | Slightly soluble Ksp = 3.3 × 10⁻⁹ |
| Calcium sulfate gypsum | CaSO₄ | Slightly soluble |
| Lead(II) chloride | PbCl₂ | Slightly soluble |
| Copper(II) hydroxide | Cu(OH)₂ | Insoluble |
| Iron(III) hydroxide | Fe(OH)₃ | Insoluble |
| Aluminium hydroxide | Al(OH)₃ | Insoluble |
| Magnesium hydroxide milk of magnesia | Mg(OH)₂ | Slightly soluble |
| Zinc sulfide | ZnS | Insoluble |
| Lead(II) sulfide | PbS | Insoluble |
| Calcium phosphate | Ca₃(PO₄)₂ | Insoluble |
| Iron(II) sulfide | FeS | Insoluble |
| Mercury(I) chloride calomel | Hg₂Cl₂ | Insoluble |
Solubility data at 25°C — see CRC Handbook of Chemistry and Physics and NIST Standard Reference Data
Solubility vs Temperature
- Most solid solutes become more soluble in water as temperature increases — dissolving is typically an endothermic process so adding heat shifts the equilibrium toward more dissolved solute.
- Gases are an important exception — gas solubility decreases as temperature increases. This is why warm water holds less dissolved oxygen than cold water — critical for aquatic life in warming climates.
- A saturated solution contains the maximum amount of dissolved solute at a given temperature. A supersaturated solution contains more than the equilibrium amount — an unstable state that can rapidly precipitate when disturbed.
- The solubility product constant (Ksp) for sparingly soluble salts quantifies the equilibrium between the solid and its dissolved ions. A lower Ksp indicates lower solubility — AgCl (Ksp 1.8 × 10⁻¹⁰) is far less soluble than NaCl (effectively fully soluble, no Ksp).
Solubility Predictor
Select a cation and anion to instantly determine the solubility of the resulting compound and see the relevant general chemistry rule.
Frequently Asked Questions
What does soluble mean in chemistry?
Soluble means a substance dissolves readily in a given solvent — usually water. A compound is considered soluble if more than approximately 1 gram dissolves per 100 mL of water at room temperature.
Are all nitrates soluble?
Yes — all nitrate (NO₃⁻) compounds are soluble in water. This is one of the unconditional solubility rules.
Is silver chloride soluble?
No — silver chloride (AgCl) is insoluble in water with a very small Ksp of 1.8 × 10⁻¹⁰. This insolubility is used analytically — adding silver nitrate to a chloride-containing solution produces a white precipitate of AgCl confirming the presence of chloride ions.
Why is calcium carbonate insoluble?
Calcium carbonate (CaCO₃ — limestone and chalk) is only very slightly soluble in pure water. However it dissolves much more readily in acidic solutions — this is why acid rain dissolves limestone buildings and why caves form through acidic groundwater dissolving calcium carbonate rock.
What does Ksp mean?
Ksp is the solubility product constant — an equilibrium constant for the dissolution of a sparingly soluble ionic compound. A lower Ksp value means lower solubility in water — the compound has a greater tendency to remain as an undissolved solid.
Are all Group 1 metal compounds soluble?
Yes — all compounds containing Group 1 metal cations (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺) are soluble in water. This is one of the most important and unconditional of the solubility rules.
What is a precipitate?
A precipitate is an insoluble solid that forms when two solutions are mixed and the resulting ion concentrations exceed the Ksp of a sparingly soluble compound. For example mixing silver nitrate and sodium chloride solutions produces a white precipitate of silver chloride.
Does temperature affect solubility?
For most solid solutes solubility increases with temperature — dissolving is typically endothermic. Gas solubility in water decreases with rising temperature — gases are less soluble in warm water than cold water.