Question

Which has maximum paramagnetic nature ?

• A. ${\left[Cu{\left(H_{2}O\right)}_4\right]}^{2+}$
• B. ${\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}$
• C. ${\left[Mn{\left(H_{2}O\right)}_6\right]}^{2+}$
• D. ${\left[Fe(CN{)}_6\right]}^{4-}$

Answer 1

Answer: (C)

(i) ${\left[Cu{\left(H_{2}O\right)}_4\right]}^{+2}C{u}^{+2}=3d^9$ No. of unpaired $e^{-}=1$
(ii) ${\left[Cu{\left(N{H}_3\right)}_4\right]}^{+2}C{u}^{+2}=3d^9$

No. of unpaired electron $=1$
(iii) $M{n}^{+2}=3d^{5}4s^0$ No. of unpaired $e^{-}=5$

No. of unpaired electron $=0$