Question

The magnetic moment of \( \text{Mn}^{3+} \) is:

• A. \(1.73 \, \text{BM} \)
• B. \(2.83 \, \text{BM} \)
• C. \(4.90 \, \text{BM} \)
• D. \(5.92 \, \text{BM} \)

Hint:

Use the formula \( \mu = \sqrt{n(n+2)} \, \text{BM} \) for calculating magnetic moment, where \(n\) is the number of unpaired electrons.

Answer 1

The Correct Option is C

Atomic number of manganese (Mn) = 25
Electronic configuration of Mn: \([Ar] \, 3d^5 \, 4s^2\)
So, Mn\(^{3+}\) loses 3 electrons → \([Ar] \, 3d^4\) Number of unpaired electrons in \(3d^4\) = 4 Magnetic moment \( \mu = \sqrt{n(n+2)} \, \text{BM} \), where \(n\) is the number of unpaired electrons \[ \mu = \sqrt{4(4+2)} = \sqrt{24} \approx 4.90 \, \text{BM} \]