What are the top eight deposits?

The eight main precipitates are AgCl (silver chloride), BaSO4 (barium sulfate), CaCO3 (calcium carbonate), BaCO3 (barium carbonate), Al(OH)3 (aluminum hydroxide), Mg(OH)2 (magnesium hydroxide), Cu(OH)2 (copper hydroxide) and Fe(OH)3 (iron hydroxide).

Among them, AgCl, BaSO4, CaCO3, BaCO3, Al(OH)3 and Mg(OH)2 are white precipitates, Cu(OH)2 is blue flocculent precipitate, and Fe(OH)3 is reddish brown precipitate. Silver chloride and barium sulfate are insoluble in acid, calcium carbonate and barium carbonate have bubbles in acid, and magnesium hydroxide, aluminum hydroxide, iron hydroxide and copper hydroxide have no bubbles in acid.

Extended data:

Silver chloride, molecular formula AgCl, molecular weight 143.32. Appearance is white powder, unstable, easy to decompose into purple and gradually turn black. The solubility in water at 25℃ is 1.93 mg/L. Hydrochloric acid can reduce its solubility in water, and can be dissolved in ammonia, sodium cyanide, sodium thiosulfate and mercury nitrate solution. Insoluble in ethanol and dilute hydrochloric acid.

Copper hydroxide (molecular formula is Cu(OH)2) is a blue flocculent precipitate, insoluble in water, decomposed by heat, slightly amphoteric, soluble in acid, ammonia water and sodium cyanide, soluble in alkaline glycerol solution, heated to 60-80℃ to turn black, and decomposed into black copper oxide and water at higher temperature.

Baidu Encyclopedia-Eight Precipitates