Coordination Compounds — Medium JEE chemistry MCQ
In the complex $[\text{Co}(\text{en})_2\text{Cl}_2]^+$, the oxidation state and coordination number of cobalt are respectively:
- A. +2 and 4
- B. +3 and 6
- C. +2 and 6
- D. +3 and 4
Solution
In $[\text{Co}(\text{en})_2\text{Cl}_2]^+$:
- en (ethylenediamine) is a neutral bidentate ligand
- Cl⁻ has -1 charge
Let oxidation state of Co = x
$x + 2(0) + 2(-1) = +1$
$x - 2 = +1$
$x = +3$
Coordination number:
- 2 en ligands × 2 donor atoms each = 4
- 2 Cl ligands × 1 donor atom each = 2
- Total coordination number = 6