Calculate the `EAN` of the central metal in the following complex
(a) `[AuCI_(2)]^(Θ)` ,(b) `[AI(C_(2)O_(4))_(3)]^(3-)`,(c ) `[(CdI)_(4))]^(Θ)` .

Explanation

Oxidation state of Au in `[AuCI_(2)]^(Θ)` is
`x + 1 (-1) xx 2 = - 1)`
`implies x = +1`
EAN of Au in `[AuCI_(2)]^(Θ)` is
Atomic number of Au - Oxidation state of Au + number of electrons gained by donation from ligands
`=79 -1 + 4 =82`
For EAN rule total electrons in the above compound should be 86 next noble gas `Rn(Z = 86)` Hence
EAN rule in the above copounds is not valid
(b) Oxidation state of Al in `[A1(C_(2)O_(4))_(3)]^(3-)` is
`x + (-2) xx 3 = -3`
` x = +3`
EAN of A1 in `[A1(C_(2)O_(4))_(3)]^(3-)`
Atomic number of A1 - Oxidation state of A1 number of electrons gained by donation from ligands
Note (en) is bidentate ligand and `C_(2)O_(4)^(2-)` is identate ligand
EAN of A1 in `[A1(C_(2)O_(4))_(3)]^(3-)`
`=13 -3 + 2(3 xx 2) = 22`
For EAN rule total electrons should be 36 next noble gas `Kr(Z=36)`
So EAN rule is not valid in the above compounds
`[(CdI)_(4)]^(Θ)`
Oxidation state of Cd in `[(CdI)_(4)]^(Θ)` is
` x + (-1) x 4 = - 1`
` x + = +3`
EAN of Cd in `[(CdI)_(4)]^(Θ)`
=Atomic number - Oxidation state of Cd+ number of electrons gained by donation from ligands
`= 48 -3+8=53`
For EAN rule total electrons should be 54 next noble gas Xe with `(Z =54)`
So EAN rule is not valid in the above compound .