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QJEEM20Ch0a99: JEE Main 2020 Chemistry - Class 12 JEEM20Ch0a99 Solution: Consider that a d 6 metal ion (M 2+ ) forms a complex with aqua …

Consider that a d6 metal ion (M2+) forms a complex with aqua ligands, and the spin only magnetic moment of the complex is 4.90 BM. The geometry and the crystal field stabilization energy of the complex is

Multiple Choice Options

  • A tetrahedral and – 1.6 Δ\Delta t + 1P
  • B octahedral and –2.4 Δ\Delta 0 + 2P
  • C tetrahedral and –0.6 Δ\Delta t
  • D octahedral and –1.6 Δ\Delta 0

Step-by-Step Verified Solution

Spin only magnetic moment = 4.9 = n(n+2)\sqrt {n\left( {n + 2} \right)}

From this, n = 4 (unpaired electrons)

(A) In octahedral complex: [M(H2O)6] 2+ JEE Main 2020 (Online) 2nd September Morning Slot Chemistry - Coordination Compounds Question 202 English Explanation 1

C.F.S.E. = (–0.4 Δ\Delta 0) × 4 + (+0.6 Δ\Delta 0) × 2 + 0 × P
= –0.4 Δ\Delta 0

(B) In tetrahedral complex: [M(H2O)4] 2+

JEE Main 2020 (Online) 2nd September Morning Slot Chemistry - Coordination Compounds Question 202 English Explanation 2
C.F.S.E. = (–0.6 Δ\Delta t) × 3 + (+0.4 Δ\Delta t) × 3 + 0 × P
= –0.6 Δ\Delta t

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