JEE Main & Advanced
JEE Main Online Paper (Held On 23 April 2013)
question_answer
The magnetic moment of the complex anion \[{{[\operatorname{Cr}(\operatorname{NO})(\operatorname{N}{{\operatorname{H}}_{3}})(\operatorname{C}{{\operatorname{N}}_{4}})]}^{2-}}\]is:
JEE Main Online Paper ( Held On 23 April 2013 )
A) 5.91 BM
B) 3.87 BM
C) 1.73 BM
D) 2.82 BM
Correct Answer:
D
Solution :
In\[{{[Cr(NO)(N{{H}_{3}}){{(CN)}_{4}}]}^{2-}},\]\[C{{r}^{2+}}({{d}^{4}})\]is given as : i.e., 2 unpaired electrons \[\mu =\sqrt{2(2+2)}=\sqrt{8}=2.82\]