In the CO3^2- ion, all three C-O bonds have identical bond lengths of 136 pm. Why?
The reason why all three C-O bonds in the CO3^2- ion have identical bond lengths of 136 pm is because of the molecule's symmetry and electronic structure.
To understand this, we need to consider the molecular geometry and the electron configuration. The CO3^2- ion has a trigonal planar molecular geometry, which means that the three oxygen atoms are arranged in a flat triangle around the central carbon atom.
In terms of electron configuration, carbon has four valence electrons, and each oxygen has six valence electrons. The double bond between carbon and each oxygen contributes four electrons to the bonding orbitals, leaving two lone pairs on each oxygen. The remaining two lone pairs on the central carbon atom also contribute to the overall electron distribution.
Now, due to the trigonal planar geometry and the repulsion between electron pairs, the molecule tries to minimize electron-electron repulsion by arranging the bonding and lone pairs as far apart as possible. One efficient way to achieve this is to have all the C-O bonds in the CO3^2- ion to have equal bond lengths.
This equal bond length is a consequence of the resonance structure of the CO3^2- ion. In this case, the double bond between carbon and each oxygen atom alternates between the three oxygen atoms in a resonating manner. As a result, the electrons in the double bonds are delocalized and distribute their electron density equally over all three oxygen atoms. This causes all three C-O bonds to have identical bond lengths of 136 pm. Resonance helps stabilize the molecule and lower its energy by allowing for electron delocalization.
In summary, the CO3^2- ion has identical bond lengths for all three C-O bonds (136 pm) due to the molecule's trigonal planar geometry, the repulsion between electron pairs, and the resonance structure which delocalizes the electron density among all three oxygen atoms.
The reason why all three C-O bonds in the CO3^2- ion have identical bond lengths of 136 pm is due to the molecular symmetry of the carbonate ion.
The carbonate ion (CO3^2-) has a trigonal planar molecular geometry, which means it has a flat, triangular shape. In this geometry, all three C-O bonds lie in the same plane, with the carbon atom at the center and the oxygen atoms surrounding it.
Since the carbonate ion is symmetrical and has equal bonding interactions with each oxygen atom, the bond lengths are identical. This symmetry occurs because all the oxygen atoms are equivalent in terms of their electron density and their distance from the central carbon atom. Consequently, this leads to all three C-O bonds having the same bond length of 136 pm.