Question

Sulfate ion point group

Answer 1

The sulfate ion (SO4^2-) belongs to the point group D4h. This point group has the following symmetry elements:

- Identity (E)
- Four C4 rotation axes passing through the sulfur atom and perpendicular to the plane of the ion
- Two C2 rotation axes passing through the oxygen atoms and perpendicular to the plane of the ion
- Four C2 rotation axes passing through the sulfur atom and bisecting the oxygen atoms
- Two C2 rotation axes passing through the sulfur atoms and parallel to the plane of the ion
- Four C2 rotation axes passing through the oxygen atoms and bisecting the sulfur atoms
- Two mirror planes perpendicular to the plane of the ion, one passing through the sulfur atom and the other bisecting the oxygen atoms
- A vertical mirror plane passing through the sulfur and oxygen atoms simultaneously
- A horizontal mirror plane passing through the sulfur atom and perpendicular to the vertical mirror plane.

In total, there are 16 symmetry elements in the D4h point group.