(a) Write the formula of the following coordination compound : Iron (III) hexacyanoferrate (II)
(b) What type of isomerism is exhibited by the complex `[Co(NH_(3))_(5)Cl]SO_(4)`?
(c) Write the hybridisation and number of unpaired electrons in the complex `[CoF_(6)]^(3-)`.
(Atomic No. of Co = 27)

Explanation

(a) `Fe^(3+) [Fe(CN)_(6)]^(x-)`
`2-6 = -x`
x = 4
`therefore " " Fe^(3+) [Fe(CN)_(6)]^(4-)`
`implies " " Fe_(4)[Fe(CN)_(6)]_(3)`
(b) `[Co(NH_(3))_(5)Cl]SO_(4)` exhibits ionisation isomerism.
`[Co(NH_(3))_(5)Cl]SO_(4)` and `[Co(NH_(3))_(5)(SO_(4))]Cl` are ionisation isomers .
(c) `[CoF_(6)]^(3-)`
`Co(27) = 3d^(7) 4s^(2)`
`Co^(+3) = 3d^(6)`
`Co^(+3)`

(under influence of F-weak ligand)
Hybridisation in `[CoF_(6)]^(3-) "is " Sp^(3) d^(2)`
Unpaired electrons are 4