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The complex ion that will lose its crystal field stabilization energy upon oxidation of its metal to +3 state is: 

 

  • Option 1)

    \left [ Co\left ( phen \right ) _{3}\right ]^{2+}

     

  • Option 2)

    \left [ Zn\left ( phen \right ) _{3}\right ]^{2+}

  • Option 3)

    \left [ Fe\left ( phen \right ) _{3}\right ]^{2+}

     

  • Option 4)

    \left [ Ni\left ( phen \right ) _{3}\right ]^{2+}

Answers (2)

best_answer

 

Coordination Entity -

Comparises of a central metal atom or ion bonded to a  fixed no of ions or molecules

- wherein

eg:

\left [ Co Cl_{3}\left ( NH_{3} \right )_{3} \right ] +\left [ Ni\left ( Co \right ) _{4}\right ]

    \downarrow                                      \downarrow

Coordination                      entity  

 

 

 

 

 

Stability of Complex -

Stability of complex is depends on nature of ligands, size of central atom and stability concept.

- wherein

Stability \alpha Stability Constant

 

 

 

Oxidation number of central metal atom -

The charge the central atom would carry if all the ligands are removed along with the electron pairs that are shared with the central atom.

-

 

 

 

 

 it is a strong field ligand.

(i) \left [ Co\left ( phen \right ) _{3}\right ]^{2+}\rightarrow\: \: \: \: \: \: \: \: \left [ Co\left ( phen \right ) _{3}\right ]^}

Co^{2+}=3d^{7}                         Co^{3+}=3d^{6}

CFSE=-1.8\bigtriangleup _{0}            CFSE=-2.4\bigtriangleup _{0}

In this case, CFSE value increase.

(ii) \left [ Zn\left ( phen \right )_{3} \right ]^{2+}\rightarrow \: \: \: \: \: \: \: \left [ Zn\left ( phen \right )_{3} \right ]^{2+}

Zn^{2+}=3d^{10}                          Zn^{3+}=3d^{9}

CFSE=0                          CFSE=-0.6\bigtriangleup _0

\therefore CFSE value increase.

(iii)  \left [ Fe\left ( phen \right )_{3}\right ]^{2+}\rightarrow \: \: \: \: \: \: \left [ Fe\left ( phen \right )_{3} \right ]^{3+}

           Fe^{2+}=3d^{6}                     Fe^{3+}=3d^{5}

       CFSE=-2.4\bigtriangleup _{0}            CFSE=-2.0\bigtriangleup _{0}

\therefore CFSE value decreases

(iv) \left [ Ni\left ( phen \right )_{3} \right ]^{2+}\rightarrow \: \: \: \: \: \: \: \: \: \: \left [ Ni\left ( phen \right ) _{3}\right ]^{3+}

           Ni^{2+}=3d^{8}                           Ni^{3+}=3d^{7}

CFSE=-1.2\bigtriangleup _{0}                       CFSE=-1.8\bigtriangleup _{0}

\therefore CFSE value increase.


Option 1)

\left [ Co\left ( phen \right ) _{3}\right ]^{2+}

 

Option 2)

\left [ Zn\left ( phen \right ) _{3}\right ]^{2+}

Option 3)

\left [ Fe\left ( phen \right ) _{3}\right ]^{2+}

 

Option 4)

\left [ Ni\left ( phen \right ) _{3}\right ]^{2+}

Posted by

Plabita

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JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

calculate cfse value on oxidation, ignore pairing energy, compare the magnitude
 

Posted by

jawahar mishra

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