karbonátionok

The carbonate ion, with the chemical formula CO3^2-, is a polyatomic anion. It consists of a central carbon atom covalently bonded to three oxygen atoms. The overall charge of the ion is -2, distributed among the oxygen atoms. This ion is planar and exhibits resonance, meaning the negative charge is delocalized across the oxygen atoms, making all carbon-oxygen bonds effectively equal in length and strength.

Carbonate is a fundamental component of many minerals, most notably carbonates like calcite (calcium carbonate, CaCO3), dolomite (calcium magnesium carbonate, CaMg(CO3)2), and aragonite. These minerals form vast geological formations and are crucial to the Earth's crust. In aqueous solutions, the carbonate ion is an important species in water chemistry, participating in acid-base reactions and buffering systems. It is also a product of the dissolution of carbon dioxide in water, forming carbonic acid (H2CO3), which then dissociates.

The presence of carbonate ions significantly influences the pH of natural waters. They are also vital in biological systems, for example, in the shells and skeletons of marine organisms such as corals and mollusks, which are primarily composed of calcium carbonate. Industrially, carbonates are used in the production of cement, glass, and various chemicals. The carbonate ion is the conjugate base of the bicarbonate ion (HCO3^-) and the conjugate base of carbonic acid (H2CO3).