Solubility Rules for Aqueous Solutions

"Sol." means that more than 3 g of the substance dissolves in 100 ml of water. "Ppt." indicates that the combination forms a precipitate.
Solubility of Aqueous Solutions
alkali Ag, Hg, Fe, Cu, other
or NH4 or Pb Ba, Sr Ca Mg Zn metals
nitrate (NO3 −),
acetate (CH3COO−),
chlorate (ClO3 −),
perchlorate (ClO4 −) 		sol. sol. sol. sol. sol. sol. sol.
fluoride (F−) sol.ppt. ppt. ppt. ppt. ppt. ppt.
chloride (Cl−),
bromide (Br−),
iodide (I−) 		sol. ppt. sol. sol. sol. sol. sol.
sulfate (SO4 2−) sol. ppt. ppt. ppt. sol. sol. sol.
carbonate (CO3 2−),
phosphate (PO4 3−) 		sol. ppt. ppt. ppt. ppt. ppt. ppt.
oxide (O 2−) form OH ppt. ppt. ppt. ppt. ppt. ppt.
hydroxide (OH−), sulfide (S 2−) sol. ppt. sol. sol. ppt. ppt. ppt.
chromate (CrO4 2−) sol. ppt. ppt. sol. sol. ppt. ppt.

Compounds that are Soluble in Water

  1. All common salts of the alkali metals (Group IA/1) or ammonium (NH4 +) are soluble.
  2. All common acetates (CH3COO−) and nitrates ( NO3 −) are soluble.
  3. All binary compounds of a metal plus a halogen (Group VIIA/17) are soluble except for fluorides (F−) and compounds containing silver (Ag), mercury (Hg), or lead (Pb).
  4. All sulfates (SO4 2−) are soluble except for those of barium (Ba), strontium (Sr), lead (Pb), calcium (Ca), silver (Ag), or mercury (Hg).

Compounds that are Insoluble in Water

  1. All carbonates (CO3 2−), phosphates ( PO4 3−), and oxides are insoluble except for alkalis (soluble compoounds rule #0.0.1).
  2. All hydroxides (OH−) and sulfides are insoluble except for alkalis (soluble compounds rule #0.0.1) and compounds containing calcium (Ca), strontium (Sr), or barium (Ba).
  3. All chromates (CrO4 2−) are insoluble except for alkalis (soluble compounds rule #0.0.1) and compounds containing calcium (Ca) or magnesium (Mg).
Figure


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On 22 Aug 2005, 02:12.