Question

Consider the following statements in respect of ${\left[CoC{l}_6\right]}^{4-}$ complex ion
I. It is paramagnate
II. It is low-spin complex
III. Oxidation number of cobalt is $-4$
IV. The coordination number of cobalt is $6$
Select the correct statement

• A. All of the above
• B. III and IV only
• C. I and IV only
• D. I and II only

Answer 1

Answer: (C)

${\left[CoC{l}_6\right]}^{4-}$
Oxidation number of cobalt $=+2$
$CN$ of cobalt $=6$

Hence, no pairing
It is thus paramagnetic and high spin complex Thus, (I) and (IV) are correct