Sum of oxidation state (magnitude) and coordination number of cobalt in $\mathrm{Na}[\mathrm{Co}(\text{bpy})\mathrm{Cl}_{4}]$ is \_\_\_\_. (Given bpy =

JEE Main · 2022 · 29 Jul 2022 · Shift 2 · Coordination Compounds

Sum of oxidation state (magnitude) and coordination number of cobalt in

Na [Co (bpy) Cl_{4}]

is ____.
(Given bpy =

Answer: 9

Solution

In the complex

Na [Co (bpy) Cl_{4}]

:

Coordination number: The ligands are one bpy (bipyridine, a bidentate ligand contributing 2 coordination sites) and four Cl⁻ ions (each monodentate). Total coordination number = 2 + 4 = 6.

Oxidation state: Let the oxidation state of Co be

x

. The overall charge of the complex ion is -1 (since Na⁺ is the counter ion).

bpy is neutral, and each Cl⁻ has charge -1:

x + 0 + 4 (- 1) = - 1

x - 4 = - 1

x = + 3

Magnitude of oxidation state = 3.

Sum = 6 + 3 = 9.

JEE Main · 2022 · 29 Jul 2022 · Shift 2 · Integer answer

Practise more: all JEE Main PYQs on Coordination Compounds →

More JEE Main questions on Coordination Compounds

Given below are two statements:

Statement I: Among $[Cu (NH_{3})_{4}]^{2 +}$ , $[Ni (en)_{3}]^{2 +}$ , $[Ni (NH_{3})_{6}]^{2 +}$ and $[Mn (H_{2} O)_{6}]^{2 +}$ , …
JEE Main 2026View solution →
Consider the transition metal ions $Mn^{3 +}, Cr^{3 +}, Fe^{3 +}$ and $Co^{3 +}$ and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes is
JEE Main 2026View solution →
A first row transition metla (M) does not liberate $H_{2}$ gas from dilute HCl .1 mol of aqueous solution of $MSO_{4}$ is treated with excess of aqueous KCN and then $H_{2} S (g)$ is passed through the solution. The amount of MS …
JEE Main 2026View solution →
Given below are two statements:

Statement I: Crystal Field Stabilization Energy (CFSE) of $[Cr (H_{2} O)_{6}]^{2 +}$ is greater than that of $[Mn (H_{2} O)_{6}]^{2 +}$ .

Statement II: Pot …
JEE Main 2026View solution →
Identify the metal ions among $Co^{2 +}$ , $Ni^{2 +}$ , $Fe^{2 +}$ , $V^{3 +}$ and $Ti^{2 +}$ having a spin-only magnetic moment value more than 3.0 BM. The sum of unpaired electrons present in the high spin octahedral complexes formed by thos …
JEE Main 2026View solution →
$[Ni (PPh_{3})_{2} Cl_{2}]$ is a paramagnetic complex. Identify the INCORRECT statements about this complex.
A. The complex exhibits geometrical isomerism.
B. The complex is white in colour.
C. The calculated spin-only magnetic moment of the complex is 2. …
JEE Main 2026View solution →