question_answer

\[M{{n}^{2+}}\] forms a complex with \[B{{r}^{-}}\] ion. The magnetic moment of the complex is 5.92 B.M. What would be the probable formula and geometry of the complex?

A) \[{{[MnB{{r}_{6}}]}^{4-}}\], octahedral

B) \[{{[MnB{{r}_{4}}]}^{2-}}\], square planar

C) \[{{[MnB{{r}_{4}}]}^{2-}}\], tetrahedral

D) \[{{[MnB{{r}_{5}}]}^{3-}}\], trigonal bipyramidal

Correct Answer: C

Solution :

[c] Magnetic moment, \[\sqrt{n(n+2)}=5.92\,B.M.\] \[\Rightarrow n\] (unpaired electrons) = 5 \[s{{p}^{3}}\] hybridization (tetrahedral)