Question

Which of the following complexes has magnetic moment of 2.83 Bohr magneton ?

• A. $\left[Ni\right(N{H}_3{)}_6{]}^{2+}$
• B. $\left[Ni\right(CN{)}_4{]}^{2-}$
• C. $TiC{l}_4$
• D. $\left[CoC{l}_6\right]$

Answer 1

The correct option is A $\left[Ni\right(N{H}_3{)}_6{]}^{2+}$

As we know,
magnetic moment
$\mu =\sqrt{n(n+2)}$ BM
n = no of unpaired electron
when n= 2
$\mu =\sqrt{n(n+2)}=2.83$ BM
$\left[Ni\right(N{H}_3{)}_6{]}^{2+}$
+2 n = 2
$\left[Ni\right(CN{)}_4{]}^{2-}$
+2 n = 0 due to pairing and low spin complex
$TiC{l}_4$
+4 n =0
$\left[CoC{l}_6\right]$
+6 n =3