Most metal carbonate compounds are insoluble in the water and few metal carbonates compounds are soluble in the water. When metal carbonate is insoluble in water, a white or other colour precipitate forms in the water. In this tutorial, we will study how solubility of metal carbonate vary from metal to metal.
Content
Considering the most of the metal carbonates, carbonates compounds of alkaline metals except lithium carbonate are soluble in water and give colourless aqueous solutions.
Francium is a very rare in nature and so we do not know its chemistry in detail Therefore, unfortunately we do not know much about Francium carbonate. In addition to above mentioned four alkaline metal carbonates, ammonium carbonate is also soluble in water, but ammonium cation is not a metal cation.
| Alkaline metal carbonate | Solubility Value |
|---|---|
| Sodium carbonate | 30.7 g/100 g water at 250C |
| Potassium carbonate | 111 g/100 g water at 250C |
| Rubidium carbonate | Very soluble |
| Cesium carbonate | 260.5 g in 100 mL of water |
All alkaline earth metal carbonate compounds, d block metal carbonate compounds and p block metal compounds are insoluble in water.
All alkaline earth metal carbonate compounds are insoluble in water and form white precipitates.
All 3d metal carbonates are insoluble in water and form colourful precipitates in the water.
| 3d metal carbonate | Chemical formula | Colour |
|---|---|---|
| Scandium carbonate | Sc2(CO3)2 | White |
| Chromium carbonate | Cr2(CO3)2 | Green |
| Manganese carbonate | MnCO3 |
|
| Iron(II) carbonate / Ferrous carbonate | FeCO3 | Precipitates as a white solid |
| Iron(III) carbonate / Ferric carbonate | Fe2(CO3)2 | Brown precipitates |
| Nickel(II) carbonate | NiCO3 | Green |
| Copper(II) carbonate | CuCO3 | Green |
| Zinc carbonate | ZnCO3 | White |
In this section, we are going to discuss solubility and colours of p block metal carbonate compounds.
Aluminium carbonate is not stable in the water and hydrolysis to aluminium hydroxide, white precipitate in the water.
A white precipitate, and toxic due to lead ion occurrence.
When solubility of metal carbonate is given for 100 ml, you can see, solubility is low or high. If solubility is like 0.005 g/100 ml water, solubility is very low and precipitates in the water.
Solubility of sodium carbonate and calcium carbonate are 30.7 g/100 g water and 0.0013/100 g respectively at 250C. You can see the difference of values. Earlier, in this tutorial, you have learned, solubility of alkaline earth metals is very low compared to the alkali metals. So that is proved by those experiment values.
Questions
Silver carbonate (Ag2CO3) is an odorless yellow to brown solid and insoluble in water.
Metal carbonates soluble in acids and gives carbon dioxide, water and respective metal salt.