Question

Which one of the following complexes is diamagnetic in nature?
(1) $K _{2}\left[ Ni ( CN )_{4}\right]$
(2) $\left[ Ni \left( H _{2} O \right)_{6}\right]\left( NO _{3}\right)_{2}$
(3) $\left[ Co \left( NH _{3}\right)_{6}\right] Cl _{3}$
(4) $\left[ Pt \left( NH _{3}\right)_{4}\right] Cl _{2}$
Select the correct answer

• A. 1 and 2
• B. 2 and 3
• C. 1,2 and 4
• D. 1,3 and 4

Answer 1

Answer: (D)

As $\left[ Ni \left( H _{2} O \right)_{6}\right]\left( NO _{3}\right)_{2}$ has two unpaired electrons, so it will be paramagnetic, while rest complexes are diamagnetic in nature as they do not have any unpaired electron.