question_answer

Which has maximum paramagnetic nature?

A)  \[[Fe{{(CN)}_{6}}{{[}^{4-}}\]     

B)  \[{{[Cu{{({{H}_{2}}O)}_{4}}]}^{2+}}\]

C)  \[{{[Zn{{(N{{H}_{3}})}_{4}}]}^{2+}}\]     

D)  \[{{[Mn{{({{H}_{2}}O)}_{6}}]}^{2+}}\]

Correct Answer: D

Solution :

                 Key Idea Paramagnetic character \[\propto \] number of unpaired electrons  \[{{[Fe{{(CN)}_{6}}]}^{4-}}\] Iron is in +2 oxidation state.                 There is no unpaired electron in \[[Fe{{(C{{N}_{6}}]}^{4-}}\]. So, it is diamagnetic.  \[{{[Cu{{({{H}_{2}}O)}_{4}}]}^{2+}}\] Copper is in +2 oxidation state.                 There is one unpaired electron. So, it is paramagnetic.  \[{{[Zn{{(N{{H}_{3}})}_{4}}]}^{2+}}\] zinc is in +2 oxidation state.                 There is no unpaired electron. So, it is diamagnetic.  \[{{[Zn{{(N{{H}_{3}})}_{4}}]}^{2+}}\] Mn is in +2 oxidation state. In \[{{[Mn{{({{H}_{2}}O)}_{6}}]}^{2+}}\]  there are five unpaired electrons. So, it has maximum paramagnetic character.