question_answer

Which of the following differs in BAN?

A)  \[[Co{{(N{{H}_{3}})}_{6}}]C{{l}_{3}}\]

B)  \[{{K}_{4}}[Fe{{(CN)}_{6}}]\]

C)  \[{{K}_{2}}[ZnC{{l}_{4}}]\]

D)  \[{{K}_{2}}[Hg{{I}_{4}}]\]

Correct Answer: D

Solution :

The total number of electrons on the central atom, including those gained from ligands in the bonding is called the effective atomic number of the central metal ion. (a) \[[Co{{(N{{H}_{3}})}_{6}}]C{{l}_{3}}\] Electrons in \[C{{o}^{3+}}\] ion \[=27-3=24\] electrons Electrons donated by \[6(:N{{H}_{3}})=2\times 6=12\]electrons EAN of \[Co(III)\]  is \[[Co{{(N{{H}_{3}})}_{6}}]C{{l}_{3}}=36\] electrons. (b) \[{{K}_{4}}[Fe{{(CN)}_{6}}]\] Electrons in \[F{{e}^{2+}}\] ion \[=26-2=24\] electrons Electrons donated by \[6(:\overset{-}{\mathop{C}}\,N)=2\times 6=12\] electrons EAN of \[Fe(II)\] in \[{{K}_{4}}[Fe{{(CN)}_{6}}=36\] electrons (c) \[{{K}_{2}}[ZnC{{l}_{4}}]\] Electrons in \[Z{{n}^{2+}}\] ion \[=30-2=28\] electrons Electrons donated by electrons EAN of \[Zn(II)\] in \[{{K}_{2}}[ZnC{{l}_{4}}]=36\] electrons                 (d) \[{{K}_{2}}[Hg{{I}_{4}}]\] Electrons in \[H{{g}^{2+}}\] ion  \[=80-2=78\] electrons Electrons donated by  electrons EAN of  \[Hg(II)\]in \[{{K}_{2}}[Hg{{I}_{4}}]=86\] electrons