Question

According to Werner's theory the primary valency and secondary valency in complex $\left[Co\right(N{H}_3{)}_{4}C{l}_2]Cl$ is respectively:

• A. 3,3
• B. 3, 6
• C. 6, 3
• D. 4, 2

Answer 1

Answer: (B)

3, 6

The primary valency is the oxidation state of the metal ion and the coordination number of the metal is the secondary valency of the metal ion.

The oxidation number of $Co=x+0-3=0$

$x=3$

The primary valency is 3 and the secondary valency is 6. Therefore, the correct option is B.