From left: Lead(II) iodide (Yellow), Barium sulphate (White) and Copper(II) carbonate (Green)

Insoluble salts are salts that does not dissolve in water at room temperature. Insoluble salts are prepared by the precipitation method through a double decomposition reactions.

In this reaction, the precipitate of insoluble salt is formed when two different solutions that contains the cation and anion of the insoluble salt are mixed. The insoluble salt is obtained as a residue of a filtration.

Read the preparations of these insoluble salts at this link: Amali Kimia: Preparations Of Insoluble Salt

REMARKS: Do the experiments and then you'll know.....