Home/
Competitive Exams/
JEE Main & Advanced/
Chemistry/
Coordination Compounds/
Question 740010
JEE Chemistry · Hard

Coordination Compounds: JEE Main MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
JEE MainHardQuestion 740010

Question

The magnetic moment (spin only) of [Fe(CN)₆]³⁻ is approximately:
  1. A
    1.73 BM (1 unpaired e⁻)
    Correct
  2. B
    5.92 BM (5 unpaired e⁻)
  3. C
    3.87 BM (3 unpaired e⁻)
  4. D
    0 BM (diamagnetic)

Correct answer

1.73 BM (1 unpaired e⁻)

Explanation

Fe³⁺ is d⁵. CN⁻ is a strong field ligand → large Δo → all electrons pair up in t₂g. Configuration: t₂g⁵ eg⁰ → 1 unpaired electron. μ = √(n(n+2)) = √(1×3) = √3 ≈ 1.73 BM.

Review Coordination Compounds notesStart timed chapter practice