question_answer

Which of the following paramagnetic ions would exhibit a magnetic moment (spin only) of the order of 5 BM? (At. Nos. Mn = 25, Cr = 24, V = 23, Ti =22)

A) \[M{{n}^{2+}}\]

B) \[T{{i}^{2+}}\] 

C) \[{{V}^{2+}}\]                       

D) \[C{{r}^{2+}}\]

Correct Answer: D

Solution :

[d]

Ion	Electronic Configuration	Magnetic moment \[\left( \sqrt{n(n+2)} \right)\]
\[C{{r}^{2+}}\]	\[{{d}^{4}}\]	\[\sqrt{4(4+2)}=4.9\]
\[M{{n}^{2+}}\]	\[{{d}^{5}}\]	\[\sqrt{5(5+2)}=5.8\]
\[T{{i}^{2+}}\]	\[{{d}^{2}}\]	\[\sqrt{2(2+2)}=2.4\]
\[{{V}^{2+}}\]	\[{{d}^{3}}\]	\[\sqrt{3(3+2)}=3.8\]

Hence \[C{{r}^{2+}}\] has magnetic moment of the order of 5 B.M.