Consider the following two complex ions : `[CoF_(6)]^(3-)` and `[Co(C_(2)O_(4))_(3)]^(3-)`. Which of the following statement(s) is/are false ?
I. Both are octahedral
II. `[Co(C_(2)O_(4))_(3)]^(3-)` is diamagnetic while `[CoF_(6)]^(3-)` is paramagnetic .
III. Both are outer orbital complexes .
IV. In both the complexes the central metal is in the same oxidation state .

Options

A. II and III
B. II, III and IV
C. II only
D. III and IV

Answer

C

Explanation

`[CoF_6]^(3-)` is an outer orbital complex as well as paramagnetic . ( For structure consult section 9.10 .
`[Co(C_(2)O_(4))_3]^(3-)`
In case `(C_(2)O_4)^(2-)` ion is a strong field ligand and will lead to pairing of electrons

six pair of electronds from three `(C_(2)O_(4))^(2-)` ions (ligands) . The complex is diamagnetic as well as inner orbital complex.