Question #77ee9

1 Answer
Feb 13, 2017

Answer:

Note that iron is NOT a main group element, and thus it does not really follow the octet rule.

Explanation:

For iron, #Z=26#

The full electronic configuration of the iron atom is:

#1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^6#

OR #[Ar]4s^(2)3d^(6)#

As is standard for a transition metal, upon oxidation, the #4s# electrons are removed FIRST to give #"ferrous ion"#, #Fe^(2+)#:

#1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^6#

And further oxidation can occur to give #"ferric ion"#, #Fe^(3+)#:

#1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^5#.

In general, iron exhibits #Fe(II+)# and #Fe(III+)# oxidation states......