Question

Carbon and silicon both belong to the group $14$, but
inspite of the stoichiometric similarity, the dioxides, (i.e., carbon dioxide and silicon dioxide), differ in their structures. Comment.

Answer 1

Due to its small size, Carbon atom forms stable $p\pi -p\pi$ bonding with itself and other small atoms like $OandN$. In $C{O}_2$, each O atom effectively forms pi bonding with 𝐶 atom, it occurs because $2p$ orbital of 𝐶 atom can effectively overlap with $2p$ orbitals of $O$ atoms to form $p\pi -p\pi$ bonds. In $C{O}_2$, both the oxygen atoms are linked with carbon atom by double bonds, and it have linear structure.


However, silicon shows its reluctance in forming $p\pi -p\pi$ multiple bonding due to large atomic size. Thus, in $Si{O}_2$ , oxygen atoms are linked to silicon atom by single covalent bonds giving rise to $3D$ network solid.