metalcarbonate

Metal carbonates are inorganic compounds composed of metal cations and carbonate anions (CO3^2-). These compounds typically form crystalline solids that are often insoluble or only sparingly soluble in water. Metal carbonates can be naturally occurring minerals or synthesized for various industrial applications.

The structure of metal carbonates generally involves the coordination of metal cations with carbonate groups, which are trigonal planar with resonance stabilization. The bonding type varies depending on the metal involved; for example, alkaline earth metal carbonates such as calcium carbonate (CaCO3) and magnesium carbonate (MgCO3) are predominantly ionic, whereas transition metal carbonates may exhibit more complex bonding.

Metal carbonates have a range of applications. Calcium carbonate is widely used as a building material (limestone, marble), a filler in plastics, paints, and paper, and as a dietary supplement. Magnesium carbonate serves as a drying agent, antacid, and in sports applications like gymnastics chalk. Other metal carbonates, such as copper carbonate (CuCO3), are used as pigments, and some are investigated for catalytic properties.

Most metal carbonates can be prepared by reacting soluble metal salts with sodium carbonate or other carbonate salts. They decompose upon heating, releasing carbon dioxide and forming metal oxides. For instance, heating calcium carbonate yields calcium oxide (lime) and carbon dioxide, a process relevant in cement manufacturing and lime production.

Overall, metal carbonates are an important class of compounds in geology, industry, and environmental science, valued for their chemical stability, versatility, and role in natural mineral cycles.