JEE Main · 2021 · 25 Jul 2021 · Shift 2 · Coordination Compounds

WhatsApp Email

The spin only magnetic moments (in BM) for free Ti³⁺, V²⁺ and Sc³⁺ ions respectively are (At. No. Sc: 21; Ti: 22; V: 23)

(A)1.73, 0, 3.87
(B)0, 3.87, 1.73
(C)3.87, 1.73, 0
(D)1.73, 3.87, 0✓ Correct

Answer: (D)

Solution

Electrons leave the

4 s

level before the

3 d

level. Titanium,

Z = 22

, gives

T i^{3 +} = [Ar] 3 d^{1}

; vanadium,

Z = 23

, gives

V^{2 +} = [Ar] 3 d^{3}

; scandium,

Z = 21

, gives

S c^{3 +} = [Ar] 3 d^{0}

. The numbers of unpaired electrons are therefore 1, 3 and 0, and the spin-only formula

μ = n (n + 2)

BM gives

μ (T i^{3 +}) = 3 = 1.73, μ (V^{2 +}) = 15 = 3.87, μ (S c^{3 +}) = 0

The spin-only magnetic moments are 1.73 BM, 3.87 BM and 0 BM respectively.

JEE Main · 2021 · 25 Jul 2021 · Shift 2 · Single correct option

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 →