#### Arrange the following Cobalt complexes in the order of incresing Crystal Field Stabilization Energy (CFSE) value. Complexes :  Choose the correct option : Option: 1 Option: 2 Option: 3 Option: 4

As we have learnt ,

The CFSE depends upon the nature of ligands if the metal cation is the same.

Also, cations having greater positive charge have a greater CFSE.

Thus, the given complexes can be arranged in order of their CFSE as

$\mathrm{\underset{\textbf{D}}{\left [ Co\left ( en \right )_{3} \right ]^{3+}}> \underset{\textbf{C}}{\left [ Co\left ( NH_{3} \right ) _{6} \right ]^{3+}}>\underset{\textbf{A}} {\left [ CoF_{6} \right ]^{3-}}> \underset{\textbf{B}}{\left [ Co\left ( H_{2}O \right )_{6} \right ]^{2+}}}$

Hence, the correct answer is option (1)