Q58 · CSIR NET Chemistry, December 2012
Paper: CSIR NET December 2012 · Subject: Inorganic Chemistry · Chapter: Lanthanides and Actinides · Topic: Lanthanides & Actinides – General · Marks: 2 · Difficulty: Hard
Consider the ions Eu(III), Gd(III), Sm(II) and Lu(III). The observed and calculated magnetic moment values are closest for the pair
(a)Gd(III), Lu(III)
(b)Eu(III), Lu(III)
(c)Sm(III), Gd(III)
(d)Sm(III), Eu(III)
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
Gd(III) (f⁷, ⁸S₇/₂, no orbital contribution) and Lu(III) (f¹⁴, diamagnetic) have observed moments that match the calculated values; Sm(III) and Eu(III) deviate because of low-lying J states.
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