Question

$\left[Fe\right(H_{2}O{)}_6{]}^{2+}$ and $\left[Fe\right(CN{)}_6{]}^{4-}$ differ in

• A. Geometry, magnetic moment
• B. Magnetic moment, colour
• C. Geometry, hybridisation
• D. Hybridisation, number of unpaired electrons

Answer 1

Answer: (C)

Geometry, hybridisation

Given ${\left[{Fe\left(H_{2}O\right)}_6\right]}^{+2}$ and ${\left[{Fe\left(CN\right)}_6\right]}^{4-}$

These compound differ each other because $\left(CN\right)$ ligand is a strong ligand it pair up with unpaired electrons in the outermost shell where as $H_{2}O$ is a weak ligand.

So different in colour and magnetic moment.

Also, $\left[Fe\right(H_{2}O){]}^{2+}$ shows $s{p}^3{d}^2$ hybridization and $\left[Fe\right(CN{)}_6{]}^{4-}$ shows $d^{2}s{p}^3$ hybridization.

Since $\left[Fe\right(H_{2}O){]}^{2+}$ is high spin complex and $\left[Fe\right(CN{)}_6{]}^{4-}$ is low spin complex, they have different number of unpaired electrons.