Why Are Certain Oxidation States of Chromium More Common Than Others?

[jtkdo_16]

The most common oxidation states of chromium are +2, +3, and +6, with +3 being the most stable. +1, +4 and +5 are rare.

Questions;

1. As given above, +2, +3, and +6 are stable, what are the possible reason of there oxidation state stability ?

2. +3 was the most stable oxidation state of chromium, What is the possible rationale of +3 as being the most stable?

3. +1, +4 and +5 are considered as rare oxidation state of chromium, What is the unlikely reason for that statement?

thank you and God bless you!

 

[Borek]

Think in terms of electron configuration and crystal (or ligand) field. And it won't hurt if you will try to find some anwers on your own, before asking question.

 

[Blueshift5]

1. The stability of an oxidation state is determined by the balance between the number of valence electrons and the number of electrons needed to complete a full outer shell. In the case of chromium, +2 and +3 oxidation states have a stable half-filled d orbital, while +6 has a full d orbital. This electronic configuration makes them more stable compared to +1, +4, and +5 which do not have a half-filled or full d orbital.

2. The most common oxidation states of elements are often the most stable due to their electronic configuration and the balance between the number of valence electrons and the number of electrons needed to complete a full outer shell. In the case of chromium, +3 has a half-filled d orbital, which is more stable than +2 or +6 due to the exchange energy and electron-electron repulsion.

3. The rarity of +1, +4, and +5 oxidation states of chromium can be attributed to the electronic configuration of chromium and the stability of the other more common oxidation states mentioned. Additionally, the +1 oxidation state requires the loss of all d electrons, which goes against the trend of elements preferring to have a half-filled or full d orbital. Similarly, +4 and +5 oxidation states require the loss of more electrons, making them less favorable compared to the more stable +2, +3, and +6 oxidation states.