The major oxidation states of the Group
elements are given below along with example species for each.
From these it can be see that the major features of Group
redox chemistry are:
- Oxygen has no positive oxidation states and can only act as an oxidant.
- Autooxidation is a feature of H2O2 chemistry.
- Excluding O(-2) the negative states are good reductants.
- While S(+4) can act as an oxidant or a reductant, it is predominantly reducing.
| | O | | S | | Se | | Te |
| *most stable state | | | +6* (H2SO4) | | +6* | | +6 |
| | | | +4 (H2SO3) | | +4* | | +4* |
| | 0 (O2) | | 0 (S8) | | 0 | | 0 |
| | -1 (H2O2) | | | | | | |
| | -2* (H2O) | | -2* (H2S) | | -2 (H2Se) | | -2 (H2Te) |
The most stable state of an element is the most likely product of reaction of
- a reductant with a species containing the element in a oxidation state above its most stable state (O2 reacts with most reductants to give O(-2))
- an oxidant with an species conaining the element oxidation state below its most stable state (H2S reacts with oxidants to give S).