NEET Solved Paper 2014 Question 28
Question: Magnetic moment 2.83 BM is given by which of the following ions? (At. No. : Ti = 22; Cr = 24; Mn = 25; Ni = 28) [AIPMT 2014]
Options:
A) $ T{i^{3+}} $
B) $ N{i^{2+}} $
C) $ C{r^{3+}} $
D) $ M{n^{2+}} $
Show Answer
Answer:
Correct Answer: B
Solution:
- Magnetic moment is given by $ \mu =\sqrt{n(n+2)} $ Here, n = number of unpaired electrons
$ \Rightarrow $ $ 2.83=\sqrt{n(n+2)} $
$ \Rightarrow $ $ {{(2.83)}^{2}}=n(n+2) $
$ \Rightarrow $ $ 8.00=n^{2}+2n $
$ \Rightarrow $ $ n^{2}+2n-8=0 $
$ \Rightarrow $ $ n^{2}+4n-2n-8=0 $
$ \Rightarrow $ $ (n+4)(n-2)=0 $
$ \therefore $ $ n=2[\because ,n\ne -4] $ Among the given ions: Hence, $ N{i^{2+}} $ possesses a magnetic moment of 2.83 BM.
