Use VSEPR theory to predict the structure of these polyatomic ions: sulfite ion.
The sulfite ion (SO3^2-) consists of one sulfur atom bonded to three oxygen atoms, with a double bond between the sulfur and one of the oxygen atoms and single bonds between the sulfur and the other two oxygen atoms.
To predict its structure using VSEPR theory, we start by considering the number of electron groups around the central atom (sulfur). In this case, there are three electron groups (two single bonds and one double bond).
Next, we determine the electron geometry by considering all electron groups as bonding groups. The electron geometry is trigonal planar since there are three electron groups surrounding the central atom.
Then, we consider the arrangement of atoms in the molecule, known as molecular geometry, by considering only the atoms bonded to the central atom. In this case, since the double bond does not change the arrangement of atoms, the molecular geometry is also trigonal planar.
Therefore, the sulfite ion (SO3^2-) has a trigonal planar electron geometry and a trigonal planar molecular geometry.