We study deeply about solubility of metal carbonates, most of the carbonates are insoluble in water.įrom alkali metals, only lithium forms insoluble carbonate. Now we consider about those precipitate of anions and those precipitates colours.Ĭarbonates have a variation because there are soluble and insoluble carbonates. Metal sulfide are not soluble and they have different colours too.Ĭarbonate, sulfate, sulphite, phosphate, sulfide, chloride, bromide, iodide and more anions form precipitates with some metal ions. Precipitates of sulfides of 3d metals, d block metals and p block metal cations Precipitates list of 3d metals hydroxidesĬhromium hydroxide ( Cr(OH) 3 ) is dissolved when excess NaOH is added and give green colour solution. Below, we are listing precipitates of 3d metals with their colours according to the anion. Therefore we can use their precipitates colours to identify 3d metal ions. Most of 3d block metals precipitates show colours. Beryllium hydroxide ( Be(OH) 2 ) is an amphoteric hydroxide compound. When they are added to water, they are converted to their hydroxides. Sr(OH) 2 and Ba(OH) 2 are readily soluble and they are strong alkalis. Be(OH) 2, Mg(OH) 2 are insoluble in water.SrSO 4, BaSO 4 are white colour precipitates.All carbonates (CO 3 2-) of alkali earth metal ions are precipitatesĬaCO 3, MgCO 3, SrCO 3 are precipitates and they are white.

AgCl is a white precipitate and AgBr is a light yellow precipitate.Īlkaline earth metals forms both precipitates and solutions. But their coloursĪre different due to different halide ions. We can decide which ions (cations or anions) are in theĬompound by comparing colours of different precipitates.Įxample: Compare AgCl and AgBr precipitates. Why colours of precipitates are important?Ĭolours of precipitates help to identify compounds. Solid phase and deposited at bottom of the solution after kept it sometime to settle down. If there is a precipitate in the aqueous solution, we can see it easily. Lead +2 ion, it forms lead chloride (PbCl 2) white precipitate. As an example chloride ion can be given.Ĭhloride ion with sodium ion form sodium chloride which is highly soluble in water. But with some cation, they form precipitates. Precipitates categorized as anions and cations : This section is bit different.Precipitates of s block, p block, d block elements.

As all of the other substances are soluble in water we can rewrite the equation.In this tutorial we cover following lessons. Because it is insoluble in water we know that it is the precipitate. We would expect them to undergo a double displacement reaction with each other.īy examining the solubility rules we see that, while most sulfates are soluble, barium sulfate is not. Write the reaction and identify the precipitate.īarium chloride and potassium sulfate are both ionic compounds. The exceptions are the alkali metals and the ammonium ion.ĬaSO 4 and Ag 2SO 4 are slightly soluble.Ī solution of barium chloride is mixed with a solution of potassium sulfate and a precipitate forms. Carbonates (CO 3 -2), phosphates (PO 4 -3) and sulfides (S -2) are insoluble. The exceptions are those containing Ag +, Hg +2, and Pb +2.Ħ. Most chlorides (Cl -), bromides (Br -) or iodides (I -) are soluble. The exceptions are the alkali metal hydroxides and Ba(OH) 2.ĥ. Nitrates (NO 3 -), chlorates (ClO 3 -), and perchlorates (ClO 4 -) are soluble. Ammonium (NH 4 +) compounds are soluble.ģ. Alkali metal (Group IA) compounds are soluble.Ģ. Solubility Rules and Identifying a Precipitateġ.

Barium sulfate precipitate color