9.
APPENDIX — Solubilities of Selected Metals and Metal Compounds[1]
Aluminum and compounds Aluminum metal reacts with dilute hydrochloric acid, sulfuric acid, potassium hydroxide, and sodium hydroxide. The salts of aluminum, including sodium aluminate, aluminum fluoride, aluminum chloride, and cryolite, are all soluble in water. Arsenic and compounds Arsenic — Insoluble in hot and cold water; soluble in nitric acid. Arsenic trioxide and pentoxide — Soluble in cold and hot water, alcohol, alkalies, and hydrochloric acid; arsenic pentoxide is soluble in acids. Lead arsenate — Insoluble in cold water; soluble in hot water, nitric acid, and caustic alkalies. Calcium arsenate(s) — Insoluble in water and acids. Sodium arsenate(s) — Very soluble in water. Arsenic acid — Soluble in water and alcohol. Arsenic trisulfide — Practically insoluble in water. Barium and compounds Barium metal — Insoluble in water; soluble in alcohol. Most of the compounds of barium are soluble in (cold or hot) water, for example, barium chloride, barium oxide, barium acetate, and barium cyanide. Barium hydroxide is slightly soluble in water. Barium carbonate is insoluble to slightly soluble in water, and is soluble in acids. Beryllium and compounds Beryllium — Slightly soluble in hot water; insoluble in cold water; soluble in dilute alkalies and acids. Beryllium oxide — Insoluble in water; soluble in some acids and alkalies. Beryllium hydroxide — Insoluble in water; soluble in acids and alkalies. Beryllium fluoride — Soluble in cold and hot water, alcohol, and sulfuric acid. Beryllium sulfate — Soluble in water and concentrated sulfuric acid. Chromium and compounds Chromium reacts with dilute hydrochloric acid and sulfuric acid, but not with nitric acid. Chromium metal — Insoluble in hot and cold water. Hexavalent chromium compounds, including chromium trioxide, the anhydride of chromic acid, chromates, dichromates, and polychromates, tend to be of low solubility in water and can be subdivided into two subgroups: 1. Water-soluble hexavalent chromium compounds include chromic acid, its anhydride, and the monochromates and dichromates of sodium, potassium, ammonium, lithium, cesium, and rubidium. 2. Water-insoluble hexavalent chromium compounds include zinc chromate, lead chromate, barium chromate, and sintered chromium trioxide. NOTE: Depending on the reference [5,8], both calcium chromate and strontium chromate are listed as soluble and insoluble in water.
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